Rens, Does not sound like the symptoms for what I want to write about, but this is something you need to consider in any way: When you run sub-rate links (i.e. 1GE interface with really 155Mbps as the service) you need to make sure that you do not try to push more traffic than the link can take. This is mostly relevant for traffic bursts, which happen all the time with IP traffic. So even if on average you do not use the bandwidth, still you have short bursts whenever you start a transaction (like a file transfer etc). In order to avoid packets being dropped due to this burst on the link, the 1GE equipment before the link should be doing egress shaping to the rate (sometimes even it is good to choose a rate slightly lower then the actual rate) of the link. This would make sure that the network equipment manages the packet drops (if you have a child QOS policy) and you do not get random tail drops of the burst. This means that you need to choose the right network device that actually supports egress shaping. Be aware that many L2/L3 switches do not support this. Arie On Thu, Sep 10, 2009 at 12:55 PM, Rens <rens@autempspourmoi.be> wrote:
All the interfaces are forced to 1Gbps and full duplex.
Maybe I should give some extra info. All the traffic seems to pass ok via that link but I have seen that often OSPF adjacencies go down/up , I suspect that the HELLO packets are being dropped that pass via that link.
That's why I started to look a little deeper and do some ping tests.
-----Original Message----- From: Adam Goodman [mailto:adam@wispring.com] Sent: jeudi 10 septembre 2009 11:45 To: Rens Cc: <nanog@nanog.org> Subject: Re: Wireless STM-1 link
Sounds like this might be an Ethernet negotiaton problem
-------- Sent from my phone
On Sep 10, 2009, at 12:05 PM, "Rens" <rens@autempspourmoi.be> wrote:
Hi all,
I'm encountering a problem with a wireless STM-1 link which has a switch connected at each end.
The wireless link has Gigabit Ethernet interfaces and so have my switches.
When I ping between the 2 switches via that wireless link I'm getting a lot of pings that are lost.
The wireless link is not saturated but I'm thinking it could have to do something with the gigabit interfaces and only having 155Mbps on the link itself?
All ideas welcome.
Regards,
Rens