Re: bgp pmtud

I think this a very good question to be tested in GNS3 with wireshark.
Doing things you'll learn so much better than just reading about it. Please
let us know what you find out.

Regards,

Tom

On Thu, Nov 1, 2012 at 8:51 AM, Imran Ali <immrccie_at_gmail.com> wrote:

> Hi all,
>
> By default when bgp router sends update ...does it sets DF bit ?
> question 1
>
> in this case if the size of update packet let say is larger than
> MTU of any of transit links ..then any transit router upon reception of
> DF marked bgp update packet send an ICMP error , if icmp is filtered due
> to any firewall then originating router will not reduce the MSS and this
> results in oscilaitng bgp sessions
>
>
> http://nagendrakumar-nagendra.blogspot.com/2010/03/bgp-path-mtu-discovery.html
>
> does any one have experinced the same or can comment on this ?
>
>
> 2) if bgp path mtu is enabled by default ..then do the router undergo
> path mtu discovery ..and figures out lowest mtu of transit links and then
> adjusts the [mss = lowes mtu - (ip headers) - (tcp headers) ] ..?
>
>
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Received on Thu Nov 01 2012 - 09:54:25 ART