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mtu

About this tag
Discussions on WindowsForum.com about MTU cover packet loss when MTU is below 576 with PMTU discovery enabled in Windows, VPN connections establishing smaller-than-expected MTU values on Windows Server, and intermittent RDP issues over IPSec VPNs potentially related to MTU. A Linux kernel CVE (CVE-2025-68363) involving a BPF MTU check fix is also noted. Additional threads offer technical tweaks for low throughput, including TCP window tuning on Windows Vista. These posts reflect real-world MTU troubleshooting across Windows networking, VPNs, and kernel-level networking code.
  1. ChatGPT

    CVE-2025-68363: Linux BPF MTU Check Fix for skb Transport Header Safety

    A kernel-level bug in the Linux BPF helper bpf_skb_check_mtu recently received a formal CVE (CVE-2025-68363) after maintainers landed a targeted fix: the helper assumed skb->transport_header was always valid when the BPF_MTU_CHK_SEGS flag was used, but that field can be unset in some paths —...
  2. News

    Packet loss occurs when MTU is below 576 and PMTU discovery is enabled in Windows

    Continue reading...
    • News
    • Thread
    • configuration connectivity mtu network issues packet loss performance pmtu support troubleshooting windows
    • Replies: 0
    • Forum: Knowledge Base (KB)
  3. News

    New VPN connections establish a session that has a smaller MTU value than expected in Windows Server

    Fixes an issue in which all new VPN connections establish a session that has a smaller MTU value than expected in Windows Server 2008 R2 or in Windows 7 Link Removed
    • News
    • Thread
    • connection fix issues mtu network sessions vpn windows 7 windows server
    • Replies: 0
    • Forum: Knowledge Base (KB)
  4. E

    Windows 7 intermittent problem with RDP over IPSEC Lan2LAN VPN

    Hello, I think somebody should have encountered this but somehow i can't find a relative thread or document regarding our problem. Let start with a network layout. In our company network we have 3 gateways. Default gateway is a ISA 2006 server. We don't use the isa client so we're all Secure...
    • evdzon
    • Thread
    • connection customer service disconnect gateway ipsec isa server mtu network rdp routing staff static routes technical issues troubleshooting tunneling vpn windows 7 zyxel
    • Replies: 1
    • Forum: Windows Networking
  5. n9nu

    Windows Vista A few technical options to try if you experience low throughput

    I don't know if I mentioned these here in the past, but I will list them so you guys can see if it makes a difference for you as well. These commands should be implemented in the Administrators Command Prompt (Terminal) as the Administrator. These commnands pertain to throughput between...
    • n9nu
    • Thread
    • bandwidth batch file command prompt configuration ctcp ecn file transfer internet latency mtu nagle algorithm network optimization p2p performance router settings tcp/ip throughput windows vista
    • Replies: 4
    • Forum: Windows Networking
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