OpenWrt Forum Archive

Topic: Can I disable MSS clamping?

The content of this topic has been archived on 23 Apr 2018. There are no obvious gaps in this topic, but there may still be some posts missing at the end.

Post #1
Alex24
3 Aug 2011, 21:36

My ISP offers me a 100mbit fiber connection with a MTU of 1500. I read MSS clamping is only needed for low speed dsl connections with a MTU lower then 1500. So i guess i can disable this option?

https://dev.openwrt.org/ticket/4522

If you have a remote site that is blocking inbound ICMP fragmentation-needed messages, that site is fairly broken anyway. Any fragmentation for any reason along the path is going to make PMTU discovery break. The connection at your end is only a small part of that path.

So in summary - no, please don't make mtu_fix the default, I don't want to pay a performance cost for the sake of of some broken ISPs and servers that I don't use anyway.

(Last edited by Alex24 on 3 Aug 2011, 21:42)

Post #2
Alex24
4 Aug 2011, 15:41

bump

Post #3
cconn
4 Aug 2011, 16:20

why not just try it?  and yes if your MTU is 1500 you don't need it.

Post #4
Alex24
4 Aug 2011, 16:42

I already did yesterday, but I just want some confirmation that i did the right thing smile

Currently i'm trying to improve the routing performance by studying all settings and see what I can disable.

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