Serial frame-relay question

[rkirmeier]

I am setting up a Cisco 26xx with one Ethernet and one T1 CSU/DSU WAN module. I have included the interface config below but what I can not understand is that I cannot ping the IP of the interface even though the Line and protocol are UP. There may be some issues with the PVC and or ISP but shoud this really matter? I would think that as long as the interface is UP I should be able to ping the IP bound to it. Any info would helpful..

interface Serial0/0
ip address 141.155.127.94 255.255.255.252
no ip directed-broadcast
encapsulation frame-relay IETF
no ip mroute-cache
no fair-queue
service-module t1 timeslots 1-6
frame-relay interface-dlci 106
frame-relay lmi-type ANSI

Note: Serial0/0 Line is UP and Protocol is UP.

 

[UNIX72]

Are you trying to ping within the CLI or PC on your LAN?

 

[jeter]

Do show frame-relay pvc and show active DLCI's.
Is this for a internet access ? If so, did you set up a route ( ip route 0.0.0.0 0.0.0.0 141.155.127.93 ) usually one lower ip than the interface because it is the nework ip.
Is the circuit in test mode ( NNI ) you would have to call your telco to have this checked out or simple do a show interface serial 0/0 and look at the ( LMI ENQ SENT AND LMI STAT RCV ) should increase together. ( LMI ENQ RCV ) show a test mode in progress. The only other thing I can think of right now is to also make sure there is mo ( LOOPBACKS ) on the span. J.Fisher CCNA
Jeter@LasVegas.com

 

[rkirmeier]

The PVC I have configured is listed as "Active" but my real question here is "Shouldn't I be able to ping the serial0/0 interface IP (141.155.127.93) from the router's CLI if the serial0/0 Line is UP and protocol is UP (SHOW INT)? Verizon is the tele company and we have had nothing but problems with them.. It is possible that the "Active" PVC (DLCI 106) is not actually the internet connection but actually one of the PVCs for the other 6 private WAN connections. But even if this were true shouldn't I be able to ping the IP on the interface from the same routers CLI as long as the Line and protocols are listed as up? I realize the circuit would have to be fully functional to ping the ISPs IPs but how about the local serial interface. Note: I can see that the PVC being configured is UP and transmitting LMIs both ways..

Thanks,
Robin

 

[jeter]

The answer to your question is YES you should ne able to ping the serial ip. J.Fisher CCNA
Jeter@LasVegas.com

 

[wybnormal]

I want to add something here I ran into. I had a router with a point to point T1 that I thought I could be clever with and use a sub-interface in preperation for frame relay which was in the near future. The links came up.. protocol up.. could not ping the otherside.. could NOT ping the routers OWN serial interface.. removed subinterface and everything worked fine. The lesson? you can not do prep work to migrate to frame from P2P ahead of time

Just a FYI

Mike S
"Diplomacy; the art of saying 'nice doggie' till you can find a rock" Wynn Catlin

 

[hibit]

Yes,
You can ping the interface on the other side of the PVC. It sounds like you have checked all the L1/2 stats. You can do some debug on ICMP but be sure BOTH sides have routes to get the request and reply packets routed properly.


With regards to subinterfaces the routing is still an issue..

good luck

 

[wybnormal]

HiBit-

There was not a PVC.. it was a straight hardwired P2P with HDLC.. just like a lab but on a large scale ;-) I added a subinterface to both ends in prep for a frame circuit I knew would coming down in a few months. The routers config had been tested on the bench back to back with a T1 loopback just fine (no subinterfaces) Installed them, made a changes and while the link came up, the protocol came up, had handshaking (via debug) we could not ping the far side *OR* ping the source routers OWN interface ? Removed the subinterfaces and everything was happy. Ideas?

Mike S
"Diplomacy; the art of saying 'nice doggie' till you can find a rock" Wynn Catlin

 

[talisker]

wyb,

Are you saying that you added a sub-interface to a P2P serial interface? Please clarify this - you can only add sub-interfaces to a serial interface configured with "encapsulation frame-relay" - the IOS won't let you add a SI to a P2P interface.

rkirmeier,

A frame-relay circuit acts like a P2P in that you can't ping the local interface if the circuit isn't up. Sometimes when the interface shows UP UP, it's actually only the circuit between the router and the local frame-switch that's up and not the actual circuit to the other router. When this happens, it can be a problem between the local provider (ie Verizon) and whoever "owns" the T1 (C&W, AT&T, etc.)

Usually ISP T1's are P2P, I've never seen an ISP use frame-relay & not provide it's own router. I guess you learn somethin' new every day! B-)

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