WAN CONNECTION ?

[ITboywonder]

I have two 2500 routers I'm trying to simulate a WAN connection with.

The line protocol on the Serial interfaces on the DCE and DTE ends keep coming up and down. I believe I have the correct configurations set on the interfaces, as far as clock rate, keep alives, and cables go. Is there something I'm missing?

If anyone has any kind of input on this, it will be greatly apprecitated

I've set Serial 1 on RouterA as DCE and Serial 0 on RouterB as DTE with the following configs:
ROUTERA
interface Serial1
description WAN link to Network B
bandwidth 64
ip address 192.168.10.1 255.255.255.0
clockrate 64000

RouterA#show int s1
Serial1 is up, line protocol is down
Hardware is HD64570
Description: WAN link to Network B
Internet address is 192.168.10.1/24
MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input 00:00:03, output 00:00:06, output hang never

RouterA#sh controller serial 1
HD unit 1, idb = 0x2C1ED0, driver structure at 0x2C9490
buffer size 1524 HD unit 1, V.35 DCE cable, clockrate 64000

ROUTERB

interface Serial1
description WAN link to Network B
ip address 192.168.10.254 255.255.255.0

RouterB#sh int s1
Serial1 is up, line protocol is down
Hardware is HD64570
Description: WAN link to Network B
Internet address is 192.168.10.254/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input 06:11:44, output 00:00:09, output hang never

RouterB#sh controller serial 1
HD unit 1, idb = 0x2C1ED0, driver structure at 0x2C9490
buffer size 1524 HD unit 1, V.35 DTE cable

 

[Jsteve]

"line protocol down" indicats a layer 1 problem.

your keep alives may be dropping, try adusting one of the Bandwitdhs so that they both match. either 64 or 1500 on both ends.

bounce the intercafe and see what happens.

 

[dogbert2]

Actually, you should remove the bandwidth on both sides, so that it will set both routers to their defaults, also, copy run start, and power off and back on both routers (routers in lab environments are very stubborn on occasion).

The rule I learned in netacad for labs, is erase start (enter), then power off router, wait 15 seconds, and then power router back up again (always seemed to solve layer 1 problems, IMO).

 

[CCIEcandidate]

Bandwidth settings have nothing to do with how the line is clocked. Your clock rate command is all you need.

See this link:

http://cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/finter_r/irfacces.htm#1018151

Bandwidth statements are used by routing protocols like IGRP, EIGRP, OSPF to calculate metrics that determine the best paths to remote networks.

What you are seeing is usually remedied by "bouncing" the serial interface at either end. Performing a shut/no shut.

If this fails, you may have a faulty cable.

watch the wrap on the link.

HTH,
Nick

 

[techkiwi]

I would agree with Nick.

Above config is nice and straightforward, and should work. You could try moving everything to the Serial 0 ports on both routers to see if you have a faulty port.

Graham