<Keepalives are temporarily in throttle due to closed TCP window>

Tue Sep 15 17:28:02 UTC 2009

* Mikael Abrahamsson:

>> What does exactly the message mean and how do I stabilize this?  Any
>> help will be appreciated.
>
> This is most likely an MTU problem.

>>Does IOS enable PMTUD for BGP sessions by default these days?  The 476
>>(or something like that) MTU is unlikely an issue.  There could be a
>>forwarding bug which causes drops dependent on packet size, though.

I am not sure. I think it is, but I went ahead and put in the command
manually. 

Here is more of the configuration to do with TCP information.

ip tcp selective-ack
ip tcp window-size 65535
ip tcp synwait-time 10
ip tcp path-mtu-discovery

-----Original Message-----
From: Florian Weimer [mailto:fw at deneb.enyo.de] 
Sent: Tuesday, September 15, 2009 12:14 PM
To: Mikael Abrahamsson
Cc: Michael Ruiz; nanog at nanog.org
Subject: Re: <Keepalives are temporarily in throttle due to closed TCP
window>

* Mikael Abrahamsson:

>> What does exactly the message mean and how do I stabilize this?  Any
>> help will be appreciated.
>
> This is most likely an MTU problem.

Does IOS enable PMTUD for BGP sessions by default these days?  The 476
(or something like that) MTU is unlikely an issue.  There could be a
forwarding bug which causes drops dependent on packet size, though.