Hi,
Spot on. Thanks.
I had a thought that it could be an mtu issue but discounted it as a
keepalive is such a small packet.
I wonder therefore if when it is exchanging routes it does not bother
with keepalives, which makes sense as there not needed as the routers
are exchanging BGP packets. I was also only seeing a very small number
of routes being recieved by the customer end.
A BGP route packet is obviously bigger and therefore was too big to be
received by the router with the lower mtu.
Thanks for the help. Spot on!!
Regards
On 2019-03-03 03:56, Job Snijders wrote:
Hi,
Please confirm that the MTU settings on both the layer-2 and layer-2
components of your topology align with each other. An MTU mismatch may
result in some larger BGP packets never ariving, resulting in the
behaviour you see.
Kind regards,
Job
On Sun, Mar 03, 2019 at 03:45:05AM +0000, [email protected] wrote:
Evening All
Having a really strange one here, where keepalive messages seem to be
getting lost between 2 MX80 routers doing external BGP to each other.
The BGP session comes up ok, and then drops 30 seconds later as the
other
side does seem to be recieving the keepalive.
Now to make things more strange is I have seen this happen before
recently
with another pair of mx80's one of which is talking to one of the
current
pair fine.
So we have MX80's at ISP1-4
ISP1-ISP2 is having this issue, these are both running old versions of
Junos
and had previously been put down to this and the link had been given
up on.
ISP2-ISP3 is working fine and has been for nearly a year
Now we have ISP3-ISP4 having the same issue. Both these routers are
running
the latest version of JUNOS.
Topology of ISP1-ISP2 is
MX80 <-> Ubiquiti 10G <-> Extreme 10G <-> MX80
Topology of ISP2-ISP3
MX80 <-> Extreme 10G(as above) <-> MX80
Topology of ISP3-ISP4
MX80 <-> Juniper EX3300(virtual Chassis <-> MX80
Anyone have any ideas on this as I am drawing a blank.
Regards
