sanity check frame question
I have a Frame connection between two sites, A and B. If the router crashes at B, wouldn't A still see the DLCI for B? Is there any scenario where this wouldn't be the case? If B gets blown off the map, shouldnt A's frame interface be in at least an up/down scenario? The only reason I ask is because AT&T has been working on a 17hr outage like this and they are focusing on the CO at site B. When I asked them how clearing up a CO issue would make the DLCI reaappear at site A, they didn't have a straight answer. In my particular case, the remote site B actually has a PVC to A and C and both of those are in a down/down....these are subinterfaces on DS3's with tons of other sites working properly. If the DLCI disappeared, doesn't that suggest that someone deleted the PVC? Any insights would be helpful.... Thanks, -BM PS It would be reasonable to interpret this *partially* as a rant. I'd really like to confirm the PVC vs CO scope of the problem though.
Thus spake <Brennan_Murphy@NAI.com>
I have a Frame connection between two sites, A and B. If the router crashes at B, wouldn't A still see the DLCI for B? Is there any scenario where this wouldn't be the case? If B gets blown off the map, shouldnt A's frame interface be in at least an up/down scenario?
In theory, when the remote LMI goes down, or any part of the PVC internal to the carrier goes down, the local LMI should go INACTIVE. In practice, this is unreliable at best; for some carriers, you will always get ACTIVE status no matter what. ATM has a similar feature/problem with ILMI. The only solution is to ignore the carrier and do it yourself end-to-end (gosh, where have we heard that before?). End-to-End Keepalives for FR: http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/wan_... dfrely.htm#xtocid18 OAM Loopback for ATM: http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/wan_r... ampvc.htm#xtocid0
If the DLCI disappeared, doesn't that suggest that someone deleted the PVC?
Distinguish between INACTIVE and DELETED; those represent very different things in LMI. S
I have a Frame connection between two sites, A and B. If the router crashes at B, wouldn't A still see the DLCI for B? Is there any scenario where this wouldn't be the case? If B gets blown off the map, shouldnt A's frame interface be in at least an up/down scenario?
In theory, when the remote LMI goes down, or any part of the PVC internal to the carrier goes down, the local LMI should go INACTIVE. In practice, this is unreliable at best; for some carriers, you will always get ACTIVE status no matter what.
For a real frame relay (not the frame relay on customer end that terminates into the ATM circuit on your end) if you want the interface to go up/down or down/down when there is a problem on a line, you must configure frame relay using sub-interfaces. Works like a charm. Alex
In theory, when the remote LMI goes down, or any part of the PVC internal to
Thus spake <alex@yuriev.com> the
carrier goes down, the local LMI should go INACTIVE. In practice, this is unreliable at best; for some carriers, you will always get ACTIVE status no matter what.
For a real frame relay (not the frame relay on customer end that terminates into the ATM circuit on your end) if you want the interface to go up/down or down/down when there is a problem on a line, you must configure frame relay using sub-interfaces. Works like a charm.
With some carriers, that works. With others, it doesn't. If you want to count on it working 24x7 with any carrier, you need end-to-end checks. S
participants (3)
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alex＠yuriev.com -
Brennan_Murphy＠NAI.com -
Stephen Sprunk