Clear forticlient cache mac
Clear forticlient cache mac. 168. But still the SAML cookie seems to be saved somewhere else. SolutionIt is assumed that memory or local disk logging is enabled on the FortiGate and other log options enabled (at Protection Profile The ARP table is used to determine the destination MAC addresses of the network nodes, as well as the VLANs and ports from where the nodes are reached. Delete the filter for the MAC address table list. 4. Clear the existing user cache using the below CLI commands: # diagnose wad user clear <ID> <IP> <VDOM> - Once the user is deauthenticated, run the below commands to refresh/clear the wad cache. Jul 28, 2022 · This article describes the issue with FortiClient version 7. Learn how to configure and manage FortiSwitch devices with FortiOS, including network access control, firewall policies, and VLAN assignment. However, the connection we created in EMS will have everything grayed out and not allow to save the username. filter flags <flag bit pattern> Specify the flag bit pattern to match. Step 6: Reboot. 0 on a Mac OS. Sep 7, 2007 · Ok, another attempt; under System->Maintenance->FortiGuardCenter->WebFiltering there' s a box to fill with TTL for WF caching. config system mac-address-table Description: Configure MAC address tables. The SAML SSO user logins are saved, and user is directly getting signed in and not being asked for the MFA. I asume you dont use MAC IP, binding 2. Scope : Solution: Units that were automatically discovered by FortiGate will expire in 28 days by default if FortiGate does not see the unit in the network anymore. Jan 8, 2024 · For example, it doesn't clear the cache or search for leftover files in other directories. In removing the system's font cache, a command-line tool is available on Mac to clear font cache on Mac. Do anyone know how to clear it? Thanks! Taskkill all Forticlient processes Delete the cookie file from the Forticlient folder If I remember, the caching was also less effective if Forticlient was fully closed out and reopened regardless of if the cookie file was changed but I would have to test again. clear & May 13, 2022 · Look for host check/ MAC address check/ AV check is enabled. 6, 6. The ARP table entries are manually added with the config system artp-table command or provided by dynamic ARP inspection (DAI). There is no control on the client (workstation) side from the Fortigate, which means that the client still remains with the IP leased until the time limit. I attempted to uninstall FortiClient on my laptop but continuously got the FortiClient screen but everything was grayed out. Click on the Advanced tab. All the deleted files will appear in a new folder on the screen. I have cleared everything with Forti in /Library/Preferences and /Library/Application Support. 2 and since then Forticlient doesn't work for any of my clients. Do anyone know how to clear it? Thanks! Jul 11, 2022 · # sudo apt-get remove forticlient . 1. Remove a single ARP entry: diag ip arp delete <interface_name> <IP Address> Mar 29, 2022 · Hi, We have some issues that Mac users get a white login screen when using FortiClient and SAML, so trying to clear the SAML cookies but can´t find it. The ARP table is used to resolve the IP addresses that correspond to a network interface card’s physical MAC address, thereby determining which IP addresses can be reached directly through a link. If interface status changes or fortigate rebooted, entry will be wiped out. I asume you dont have the problem on your switch (this can also be a reason not only fortigate). Restart Teams. Right-click on the Trash icon in your dock and select ‘Empty Trash’. You can also clear browsing history, cookies, autofill data, and more if you select the Advanced tab. 50. ~/Library/Caches. Have an issue with SSL-VPN on a Fortigate 50B. Aug 6, 2022 · Try this steps to clear cookie on Mac -. Its tight integration with the Security Fabric enables policy-based automation to contain threats and control outbreaks. If the user, after a disconnect / logout, closes the Forticlient VPN interface , when he tries to reconnect he must follow the authentication Sep 5, 2007 · Hey folks. x, and configured with a DHCP server. How Do I Remove FortiClient from Startup Mac Manually? In uninstalling FortiClient on Mac manually, it may need or require some basic skills since you will do everything alone without any assistance. 20 hours ago · How you can clear Hulu cache on Mac. Redirecting to /document/fortigate/7. Jul 25, 2022 · We have some issues that Mac users get a white login screen when using FortiClient and SAML, so trying to clear the SAML cookies but can´t find it. 13 and later), just clears the address from the Fortigate database. This topic provides instructions on the necessary configurations. 2 . Note: Mar 26, 2024 · Step 4: Delete Cache From Your Mac’s Bin. Before removing FortiClient on a Mac, close it completely with one of the following methods: Oct 31, 2022 · Try this steps to clear cookie on Mac- Step 1: Terminate all running applications using the Cmd+Q key combination. end Set the number of DNS entries that are stored in the cache (0 to 4294967295, default = 5000). Although clearing the cache on Mac is no rocket science, like any technical process, it’s easy to make mistakes that can lead to unintended consequences or render the entire endeavor ineffective. Oct 31, 2022 · Note: It’s not advisable to delete cache folders. Step 2: Open a Finder window and use Shift+Cmd+G to navigate to the directory. Click on Settings/Preferences (depending on the version of macOS you are running). Restart FortiClient then it will create a new fmon_cache. Aug 19, 2005 · Find an appropreate command tou do " arp clear" (but i don think it has any) or just do a " execute ping xx. FortiClient 7. Method 3. 6) To install the newly downloaded FortiClient version: # sudo dpkg -i <forticlient file name. This value is hexadecimal. Apr 15, 2019 · The IPv6 static cache entry for neighbor discovery feature allows static entries to be made in the IPv6 neighbor cache. To view the ARP cache in the CLI: get system arp. Man was I on fire. Cache Contents Aug 15, 2022 · Note: It’s not advisable to delete cache folders. 4 Administration Guide, which contains information such as: Jun 4, 2011 · ARP table. If VDOMs are configured: config vdom edit <vdom_name> get system arp . Step 5: Do the same thing—manually delete all files inside each folder there. Solution . Solution Using the FortiGate CLI. 8 set mac bc:14:01:e9:77:02 next end Aug 19, 2005 · Find an appropreate command tou do " arp clear" (but i don think it has any) or just do a " execute ping xx. filter port-id-map <port-ID list> List the port identifiers to display MAC Feb 10, 2017 · Hello, I want to delete FortiClient traffic logs stored on FortianAlyzer that are visible in Log View->Security->Fortclient_>Traffic. CLI Syntax: config system dns. How to Clear Font Cache on Mac Completely 1. dat. Sep 28, 2021 · FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic. 8 set mac bc:14:01:e9:77:02 next end Nov 17, 2016 · This article gives the command to purge specific cached content. ScopeThe examples that follow are given for FortiOS 5. Sample output: Mar 10, 2022 · This article describes how to clear the unit inventory in particular frequent interval via the automated script. eventually all FortiClient logs. You can press Command-A on your keyboard to select all of the files and right-click on the highlighted selection Mar 29, 2022 · Note: It’s not advisable to delete cache folders. Scope FortiGate. dat in FortiClient folder . What is FortiClient?. Reinstall the FortiClient software on the system. Clear FortiClient cache. You also need to delete the cache from your Recycle Bin to permanently rid your Mac of unnecessary cache. diag vpn ike log-filter name Tunnel_1 Here are the other options for the IKE filter: list <----- Display the current filter. Mar 29, 2022 · Note: It’s not advisable to delete cache folders. Dec 6, 2023 · Delete all files and folders in the directory. Sep 29, 2015 · If you want to clear the cache file, you can. Fortianalyzer v5. Keep them to avoid any system conflicts and only delete the files inside. SolutionIn some cases (troubleshooting purposes for instance), it is required to delete all or some specific logs stored in memory or local disk. Related document: Instruction for installing FortiClient Linux 7. All programs should be Feb 15, 2010 · To clear all the DHCP address leases on a FortiGate unit, execute the following command :FGT# execute dhcp lease-clearScope FortiGate units, running FortiOS version 4. You will see a folder containing your Mac's cached files. Try this steps to clear cookie on Mac- Step 1: Terminate all running applications using the Cmd+Q key combination. 4 To clear all of the entries in the ARP table: execute clear system arp table To delete a single ARP entry from the ARP table: diagnose ip arp delete <interface name> <IP address> To add static ARP entries: config system arp-table edit 1 set interface "internal" set ip 192. Step 4: Once again, using the Shift+Cmd+G key combination, now go to the folder /Library/Caches. Nov 20, 2019 · Then on ONE of them, I did the supplemental patch. 00 MR3 or 5. # dia webfilter fortiguard cache dump . FortiOS ARP Commands: Display ARP table: get system arp . The last solution is to Delete MacOS Fortinet or FortiClient references manually: If none of them worked, as an alternate: (Forced uninstall)-Open Applications > Utilities > Terminal-Mac$ cd /-Mac$ cd Library/LaunchDaemons Aug 9, 2024 · Delete an ARP Table entry: C:\> arp -d 192. To clear your entire cache, select All time for the range, check the Cached images and files box, then click Clear data. Needless to say I was not a happy camper. deb> # sudo apt install -f . Scope . from administrative command line, run "sc stop fortishield" 3. How do I go about clearing / deleting the users cached SAML credentials for their VPN session (using AZURE MFA). Fortinet Developer Network access IPv6 MAC addresses and usage in firewall policies Cache service and video caching Fortinet Developer Network access IPv6 MAC addresses and usage in firewall policies Cache service and video caching Note: It’s not advisable to delete cache folders. This article also lists workarounds and future permanent solution. Then it DEFINITELY HAS a mac address table. -Uninstall vial unintaller in Applications folder. 8 set mac bc:14:01:e9:77:02 next end Device identification in FortiOS is based upon MAC address, therefore if the FortiGate is unable to see the client's MAC address, identification will not work. Step 1: Terminate all running applications using the Cmd+Q key combination. Thankfully, once you clear cache on Mac Catalina, it can quickly fix these annoying problems plaguing network arp. Apr 7, 2022 · We have some issues that Mac users get a white login screen when using FortiClient and SAML, so trying to clear the SAML cookies but can´t find it. Following automated script is to clear the unit inventory in every 8 To clear all of the entries in the ARP table: execute clear system arp table To delete a single ARP entry from the ARP table: diagnose ip arp delete <interface name> <IP address> To add static ARP entries: config system arp-table edit 1 set interface "internal" set ip 192. For IPv4: config system arp-table edit %value% set interface <interface-name> set IP set mac end For example: config system arp-table Dec 8, 2023 · Hi, I made the mistake of uninstalling an old version of Forticlient to install the 7. Compatible with bring-your-own-device or company-issued smartphones and desktops, Fortinet’s business communications solution enables you to seamlessly make/receive calls, check voicemail messages and do more. I gave full disk access to both Forticlient and fctservctl2. Library Cache Step 3: Manually open every folder, select all the files using Cmd+A, a Dec 22, 2021 · FortiClient 7. 2) Device identification is not complete Mar 3, 2023 · Open Safari. Part 2. If the user, after a disconnect / logout, closes the Forticlient VPN interface , when he tries to reconnect he must follow the authentication May 6, 2022 · Hi, we use FortiClient on Mac OS X to connect to our customers VPNs. Solution Learn how to view, clear, and configure the ARP table on FortiGate devices with this Fortinet documentation guide. Go to System Preferences -> Users & Groups -> Current_User > Login Items. Use this command to add or delete an address resolution protocol (ARP) table entry, or to display the ARP table. Aug 13, 2019 · * The lease-clear command, which is the same as 'Revoke Lease(s)' from the DHCP Monitor on the Dashboard (FortiOS v6. Type %appdata% and press Enter. The output will provide cache URL and its rating information. 2 would fix the Catalina problem. Fortinet Documentation Library To clear all of the entries in the ARP table: execute clear system arp table To delete a single ARP entry from the ARP table: diagnose ip arp delete <interface name> <IP address> To add static ARP entries: config system arp-table edit 1 set interface "internal" set ip 192. Clearing the FortiClient cache can help eliminate any corrupted or conflicting files that may be causing the VPN to get stuck at 98%. To do that, click the Bin icon at the bottom right of your Mac dock. 8 set mac bc:14:01:e9:77:02 next end Apr 4, 2022 · We have some issues that Mac users get a white login screen when using FortiClient and SAML, so trying to clear the SAML cookies but can´t find it. 2-build1151 161213 (GA) Fortclient v5. 1 and above. 2 from repo Nov 15, 2023 · You may resolve this issue if you clear font cache on Mac. To clear cookies from FortiClient GUI itself: 1) In this method, FortiGate will keep the arp entry until binded interface status is up or FortiGate is not rebooted. The duration that the DNS cache retains information, in seconds (60 to 86400 (1 day), default = 1800). That patch killed my FortiClient. You can access endpoint control features through the epctrl CLI command. This step is where you’ll actually remove FortiClient from your Mac. Find out how to delete different types of cache and what cache you should leave alone. 4) It is now possible to clear all logs or specific logs in such a folder. Jul 22, 2017 · Lets say hypothetically that you create a software or hardware switch on the Fortigate. ScopeFortiCache OS v4. For some reason, it may be required to clear the route cache on FortiGate. Usage. msi installer file) you can NOT uninstall from Control Pannel. 0 Jul 21, 2022 · We have some issues that Mac users get a white login screen when using FortiClient and SAML, so trying to clear the SAML cookies but can´t find it. You must sign in using an admin account to utilize the utility. It is necessary to manually add the entry again. Delete apps with third-party tools. Installing certificates on the client To configure a Windows client: Install the user certificate: Double-click the certificate file to launch Certificate Import Wizard. 7) To launch the newly installed FortiClient GUI, type this in the terminal and hit Enter: # forticlient gui. 3: Endpoint control. Is it a cookie or a temp file stored… Jun 4, 2010 · The following summarizes the CLI commands available for FortiClient (macOS) 7. Solution Route cache is a Linux kernel component that is consulted before the actual route lookup. After manually running the FortiClient installer on a macOS computer, you must enable certain permissions and perform other actions for FortiClient to work properly. Jul 27, 2024 · Clearing cache is a crucial Mac maintenance task that can enhance the browsing experience, boost system performance, and resolve technical issues. Do anyone know how to clear it? Thanks! Jan 12, 2022 · Seems Fortigate VPN makes a sort of credential cache. 4 CLI commands used to configure and manage a FortiGate unit from the command line interface (CLI). Nov 5, 2021 · FortiClient proactively defends against advanced attacks. 0 and everything was working well. Clear the ARP Table: execute clear system arp table . FortiClient. When I try to log on, it gets stuck on "connecting". But still the SAML cookie seems to be saved somewhe May 23, 2022 · MAC address: Media access control address is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment. Solution - Use the below command to dump the webfilter Cache entries in the FortiGate. You'll need third-party programs to clean them up anyway. Syntax: # diag ip arp add <interface> <ip> <mac address> Example. Caution: The password is visible in clear text; be careful when capture this command to a log file. 0: Solution: FortiClient stores the data in the following directory: <Drive>:\Users\UserName\AppData\Local\FortiClient. set fqdn-max-refresh <integer> -> FQDN cache maximum refresh time, in seconds (3600 - 86400, default = 3600). After completing these steps, FortiClient will be uninstalled from Jan 3, 2017 · With FortiEMS, I found that if we enable the "Allow personal VPN" option, you then have the option to save login and provide a username to a new connection you setup in FortiClient. Everything is working normally, we can access the web gui and bookmarks work, etc. Fortinet announced that 6. Step 3: Manually open every folder, select all the files using Cmd+A, and move everything to the Trash. edit <mac> set interface {string} set reply-substitute {mac-address} next end FortiFone Softclient lets you stay connected anywhere, anytime, without missing any important call. Method 2: Delete the files. Usually, the option to clear Hulu cache is found in your browser’s settings menu, but keep reading to find out all the ways you can clear browser cache on Mac: How to remove Hulu cache on Chrome; How to free up Hulu cache on Safari; How to delete the Hulu cache on Firefox; How to clear Hulu cache on Opera; 1. Hope this helps Edit:: the actual disconnect script I used a while back Aug 16, 2020 · how to process when troubleshooting IKE on IPSEC Tunnel. Manual Way to Delete Font Cache on Mac. However, the instant we enable the " cache clean" setting for the user group, the web browser hangs when we attempt to logout of the SSLVPN (must kill the proc Sep 7, 2007 · Ok, another attempt; under System->Maintenance->FortiGuardCenter->WebFiltering there' s a box to fill with TTL for WF caching. This You can force FortiClient to delete the cookies file on disconnect, making the user re-authenticate when they connect again. Reboot the Mac. Aug 4, 2023 · Check the boxes for the kinds of data you’d like to be cleared Clear Now. dns-cache-ttl. Entries that remain in the cache provide a quicker response to requests than going out to the Internet to get the same information. Solution: Method 1: Remove FortiClient from startup programs. Labels: FortiClient v3. 0 and 6. Delete all MAC address entries or a specific MAC address entry. Till this week I used macOS 10. Click on Safari in menu bar at top of screen. 0166 Jan 25, 2022 · -To shutdown, right-click on FortiClient icon, select 'shutdown' from menu. Press Windows Key + R to open the Run dialog box. Default value when enabled is 3600 seg This means that your FGT will store URL ratings in the cache for 1 hour without contact Fguard servers again (or until newer cache entries force the removal of the older ones) What about to change that value to force expiration? Aug 6, 2009 · The message The Fortinet Fortishield service was stopped successfully will appear and you will be able to edit and add values to the FortiClient registry. x, the old command to refresh/clear wad user/group cache doesn't exist. Flush DNS cache on Mac. This article explains why FortiClient will not prompt for credentials after first successful login using SAML method. In this article, we’ll show you how to uninstall FortiClient from your Mac. Dec 8, 2022 · "Other" Storage in Mac OS Big Sur: Can I delete Application Support files? Dear all, Main Problem: I have been dealing with the well-known "other" storage problem, a mac that overheats quickly for seemingly no reason and some other trouble (won't connect to wifi unless I deconnect the external monitor and turn of bluetooth and tons of issues with the Mail-app [although this might be connected once the FortiClient got connected it will get propagate the DNS that is configured on the SSL-VPN config to all local interfaces in the local machine, if you are using internal DNS then once there is a network interruption for a few seconds the fortiClient will try to re-connect while he is trying to resolve the FQDN with the local DNS from Apr 30, 2020 · By using this setting, the FortiGate can control the maximum interval for querying DNS updates for its FQDN addresses, allowing more control over DNS caching behavior. The great thing about third-party tools is that they delete apps with a click, along with all the unnecessary associated files, cache, etc. 3 must establish a Telemetry connection to EMS to receive license information. This document describes FortiOS 7. Jun 8, 2022 · This article describes how to collect the webfilter cache URLs, URL category rating, and cache TTL for a specific entry. Solutionexecute webcache delete [pattern_type] [pat Caution: The password is visible in clear text; be careful when capture this command to a log file. 4, 5. FortiOS CLI reference. Scope FortiGate, FortiClient or Web Browser with SAML Authentication. Solution After the first login, SAML Nov 11, 2022 · FortiGate, FortiClient. May 16, 2024 · Should you clear the cache on Mac Catalina? It's crucial to clear cache on macOS Catalina because it can help improve device speed, reclaim precious macOS Catalina storage space, and resolve minor software issues due to out-of-date cache files. For information on using the CLI, see the FortiOS 7. If the lookup into this cache does not produce a Fortinet Documentation Library Oct 31, 2022 · Note: It’s not advisable to delete cache folders. This happens only if Forticlient VPN interface is not close. 6. The ARP Table page lists the IP address, number of minutes that the ARP entry has been in the ARP table, MAC address, and interface for each ARP table entry. To view the ARP cache in the system in the CLI: diagnose ip arp list. If clients are not on the same network as FortiGate, use agent based device authentication (FortiClient). shutdown FortiClient. filter clear. 2/cli-reference. Apr 11, 2022 · Anyone have a solution or idea how to clear Forticlents SAML cookie on a MAC? The only thing we have found working is to re-install FortiClient. Library Cache. xx" (server ip). Check for compatibility issues between FortiGate and FortiClient and EMS. Clear the cache in Teams for macOS Classic Teams. FortiClient features are only enabled after connecting to EMS. Mac addresses on FortiGate can be seen: In NAT Mode. Configure MAC address tables. May 21, 2024 · To solve this, uninstall FortiClient on Mac instead by using either of the two methods presented below. diagnose test authserver ldap <server_name> <user> <password> Test user authentication using an LDAP server. But I haven't enabled the - When you install Forticlient with ON LINE installer (that internally uses a pcclient. If your keyboard is having issues, or the command keys just aren't reliable anymore, you can still clear the cache on your Mac. Follow these steps to clear the cache: Close FortiClient and ensure it is not running in the background. DNS cache records the information about previous DNS (Domain Name System) lookups that macOS stores locally in order to save time on converting the URLs of the sites you’ve visited in the past to their IP addresses. Issues at this stage usually occur due to a corrupted installation of FortiClient or due to OS problems. 8 set mac bc:14:01:e9:77:02 next end Nov 17, 2021 · how to clear the FortiGate route cache. Jul 26, 2022 · As wad maintains its own cache for user & group information. Solution: 1) If the FortiClient is connected to EMS, it needs to be disconnected: 2) 'Right-click' on the FortiClient icon in the taskbar and shutdown. The safest way to clear your Mac's system cache is to boot into Safe Mode, and then boot up normally. 2. On Windows, this can be done by adding "del /f %LOCALAPPDATA%\FortiClient\Cookies" in the "On Disconnect Script" configuration of FortiClient. It just takes Jul 1, 2024 · If your Mac previously had Fortinet software installed, it probably still has FortiClient on it, and if you no longer need it, you should uninstall it to free up space and prevent conflicts with other software in the future. delete fmon_cache. 3) Goto FortiClient installation folder (default path is C:\Program Files\Fortinet\FortiClient\logs). Library Cache Step 3: Manually open every folder, select all the files using Cmd+A, a Sep 17, 2019 · This article explains how to delete all traffic and all associated UTM logs or specific FortiGate log entries stored in memory or local disk. To clear your web browsing cache in Safari, enable the Develop menu in Safari > Settings > Advanced, then select "Empty Caches" from the Develop menu. Do anyone know how to clear it? Thanks! Mar 19, 2019 · How to clear the cache on your Mac without shortcuts. 0, thus upgraded client to 7. After a user makes logout, if he tries to reconnect, the authentication phase is skipped. In the Finder, open the /Applications/Utilities folder, and then double-click Terminal. FortiClient is compatible with Fabric-Ready partners to further strengthen enterprises’ security posture. Mar 28, 2022 · In Chrome, click the menu icon (three vertical dots) > More Tools > Clear Browsing Data. Step 2: Open a Finder window and use Shift+Cmd+G to navigate to the directory ~/Library/Caches. Cache is data a Mac uses to speed up processes, but it hogs space. To clear all of the entries in the ARP table: execute clear system arp table To delete a single ARP entry from the ARP table: diagnose ip arp delete <interface name> <IP address> To add static ARP entries: config system arp-table edit 1 set interface "internal" set ip 192. xx. Apr 11, 2024 · Empty the Trash to permanently delete FortiClient from your Mac. Aug 20, 2019 · This article explains how to delete FortiGate log entries stored in memory or local disk. Note: - Make s Nov 30, 2023 · 6. 157. - If you have installed Forticlient from OFF LINE installer, you CAN uninstall Forticlient from Control Pannel. Static routing requires an administrator to manually enter IPv6 addresses, subnet masks, gateways, and corresponding Media Access Control (MAC) addresses for each interface of each device into a table. ScopeFortiGate under Linux kernel 3. 0. Solution Filter the IKE debugging log by using this command. This will permanently delete FortiClient and any associated files. Mar 15, 2023 · To clear your Mac's application (user) cache, delete all files and folders in ~/Library/Caches. 2. If you don't understand the difference between a MAC table and an ARP table, then you probably aren't going to be able to help. This case you must use same installer and check the option "uninstall". Oct 7, 2016 · the commands to add the ip-mac address binding in both IPv4 and IPv6. There is a file in there called 'cookies' which if deleted will cause FortiClient to once again prompt for authentication. Now I upgraded to macOS 12/Monterey which didn't work with forticlient 6. Use this pattern to mask important bits. Jan 12, 2022 · Seems Fortigate VPN makes a sort of credential cache. Showing the commands available to list the MAC addresses on a FortiGate. Remove FortiClientAgent using the '-' sign. 5. 15/Catalina with forticlient 6. If Teams is still running, right-click the Teams icon in the dock, and then select Quit or press Command (⌘)-Q. In firmware version 7. Default value when enabled is 3600 seg This means that your FGT will store URL ratings in the cache for 1 hour without contact Fguard servers again (or until newer cache entries force the removal of the older ones) What about to change that value to force expiration? Apr 12, 2023 · (Image credit: Future) 3. 98%. xqxo xfc dkn czr sipdwx quxrb efxb gbut awr qckeyu