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Does Linux have an Equivalent of Windows PMTU Blackhole Router Discovery?

Does Linux have an Equivalent of Windows PMTU Blackhole Router Discovery?

Under windows there is a registry setting to enable "Blackhole Router Detection", enabling path MTU discovery to function when there are misconfigured routers / firewalls in the path blocking the ICMP fragmentation needed messages.

Asked by: Guest | Views: 57
Total answers/comments: 2
Guest [Entry]

"Yes, you can.

To quote from the linux kernel mailing list in 2008:

From: John Heffner <johnwheffner@...>
Subject: Re: PMTU Discovery - Does it work?
Date: Thursday, May 22, 2008 - 1:19 pm
Message-ID: <1e41a3230805221019u4c739527u2a9c1217d1c7411c@mail.gmail.com>

[...]

This is a well known issue (RFC 2923), and was the motivation for the
development of MTU probing (RFC 4821), enabled with tcp_mtu_probing.

John Heffner wrote the changes to the linux kernel in 2007.

so to turn on tcp_mtu_probing

# echo 2 > /proc/sys/net/ipv4/tcp_mtu_probing

Possible values

0: disabled
1: enabled when black hole detected
2: always enabled"
Guest [Entry]

"The last information that I knew was that Linux had no support for PMTU blackhole router discovery.

This is due to the Linux non-compliance of RFC 2923."