nanog mailing list archives
Re: Smallest Transit MTU
From: Sabri Berisha <sabri () cluecentral net>
Date: Wed, 5 Jan 2005 17:39:05 +0100
On Wed, Dec 29, 2004 at 05:04:11PM -0500, Joe Abley wrote:
On 29 Dec 2004, at 16:33, Tony Rall wrote:But that only affects tcp traffic - it does nothing to help other protocols.Are there any common examples of the DF bit being set on non-TCP packets?
[root@bofh sabri]# host -t ns verisign.com 192.5.6.30 Using domain server 192.5.6.30: verisign.com name server bay-w1-inf5.verisign.net [root@bofh root]# tcpdump -Xn host 192.5.6.30 tcpdump: listening on fxp0 17:37:53.124955 217.69.153.39.55058 > 192.5.6.30.53: 58565+ NS? verisign.com. (30) 0x0000 4500 003a 5f10 0000 4011 e312 d945 9927 E..:_...@....E.' 0x0010 c005 061e d712 0035 0026 8ac9 e4c5 0100 .......5.&...... 0x0020 0001 0000 0000 0000 0876 6572 6973 6967 .........verisig 0x0030 6e03 636f 6d00 0002 0001 n.com..... 17:37:53.216656 192.5.6.30.53 > 217.69.153.39.55058: 58565- 3/0/3 NS[|domain] (DF) 0x0000 4500 00ca 0000 4000 3111 1093 c005 061e E.....@.1....... 0x0010 d945 9927 0035 d712 00b6 1b79 e4c5 8100 .E.'.5.....y.... 0x0020 0001 0003 0000 0003 0876 6572 6973 6967 .........verisig 0x0030 6e03 636f 6d00 0002 0001 c00c 0002 0001 n.com........... 0x0040 0002 a300 001a 0b62 6179 2d77 312d 696e .......bay-w1-in 0x0050 6635 f5 Here you go. A root-nameserver setting the DF-bit on its replies :) -- Sabri Berisha, SAB666-RIPE - I route, therefore you are http://www.cluecentral.net - http://www.virt-ix.net http://www.bash.org/?78486
Current thread:
- Re: Smallest Transit MTU Sabri Berisha (Jan 05)
- Broken PMTUD for . + TLD servers, was: Re: Smallest Transit MTU Iljitsch van Beijnum (Jan 09)
- Re: Broken PMTUD for . + TLD servers, was: Re: Smallest Transit MTU Mark Andrews (Jan 09)
- Re: Broken PMTUD for . + TLD servers, was: Re: Smallest Transit MTU Iljitsch van Beijnum (Jan 09)
- Re: Broken PMTUD for . + TLD servers, was: Re: Smallest Transit MTU Alexei Roudnev (Jan 10)
- Re: Broken PMTUD for . + TLD servers, was: Re: Smallest Transit MTU Mark Andrews (Jan 10)
- Re: Broken PMTUD for . + TLD servers, was: Re: Smallest Transit MTU Suresh Ramasubramanian (Jan 10)
- Re: Broken PMTUD for . + TLD servers, was: Re: Smallest Transit MTU Mark Andrews (Jan 10)
- Re: Broken PMTUD for . + TLD servers, was: Re: Smallest Transit MTU Alexei Roudnev (Jan 10)
- Re: Broken PMTUD for . + TLD servers, was: Re: Smallest Transit MTU Mark Andrews (Jan 09)
- Broken PMTUD for . + TLD servers, was: Re: Smallest Transit MTU Iljitsch van Beijnum (Jan 09)