Solved: Re: Connecting two 1751 w/serial interfaces - Page 2

dal · ‎07-08-2003

I am attempting to connect to 1751 routers w/serial interfaces via t1 line. Router "A" (host side) is identical to router "B" remote side. I want to keep them on the same subnet for simplicity purposes. I have performed this feat with csu/dsu modules in the past, but never with serial interfaces. Host side has an internet gateway seperate from the router itself - which the remote side will need access to also. For the life of me I cannot figure out what I am doing wrong. This is the configuration from router "A", router "B's" configuration is identical except for the BVI 1 IP address is x.x.x.22 instead of x.x.x.21. Any help is greatly appreciated.

Using 876 out of 29688 bytes

!

version 12.2

service timestamps debug uptime

service timestamps log uptime

service password-encryption

!

hostname Cisco1

!

enable password xxxx

!

memory-size iomem 25

ip subnet-zero

no ip domain lookup

!

bridge irb

!

interface FastEthernet0/0

description connected to EthernetLAN_1

no ip address

no keepalive

speed auto

bridge-group 1

!

interface Serial0/0

description connected to CiscoB

ip unnumbered FastEthernet0/0

bridge-group 1

!

interface BVI1

ip address 192.168.0.21 255.255.255.0

!

router rip

version 2

network 192.168.0.0

no auto-summary

!

ip classless

no ip http server

!

snmp-server community public RO

snmp-server enable traps tty

bridge 1 protocol ieee

!

line con 0

exec-timeout 0 0

password xxxx

login

line aux 0

line vty 0 4

password xxxx

login

!

no scheduler allocate

end

deilert · ‎07-10-2003

Have you tried HDLC encap ? Your LCP is not coming up in PPP , If you change to HDLC encap and you still get protocol down , you need to investigate the CSU being misconfigured ,

Can tou paste in a sh serial X from the B router

dal · ‎07-10-2003

I have tried HDLC to no avail. I can post sh serial X from the B router - but that will be later as I have no connection to remote router at this point. Should I go back to HDLC at this point?

deilert · ‎07-10-2003

It is the easiest to configure , as long as it a Cisco box that is attached on the other end , I would use HDLC .

dal · ‎07-10-2003

Yes, two identical cisco 1751 brand spankin new on each side. Let me ask you another question, If the remote router "B" is still on PPP encap aand I have changed the host router "A" to HDLC - should i be able to get a s0/0 is up - line protocol up on the host side? Thanks for all your advice - has been a big help so far.

deilert · ‎07-10-2003

no you must use the same encap on each end HDLC>>>HDLC or PPP >>.PPP , If you are using boxes from differnet vendors on a point to point link you have to use PPP.

dal · ‎07-10-2003

I know for communication between the two routers each encap has to be the same. But will that in itself cause the message "int s0/0 is up - line protocol down"? I can get the "line protocol" to stay up for a minute or two - and back down.

deilert · ‎07-10-2003

Yes it will, What brings up and keeps up your line protocol the the tranmitting and receipt of keepalive packets . The line protocol will drop after 3 keepalives are missed .

dal · ‎07-10-2003

Thanks - I am heading to the remote site to switch the encap & clock rate. I had already posted the debug info before I got to this post.

deilert · ‎07-10-2003

I thought you said this is using an external CSU that is provided by the Telco , Who is providing clock , you may not need to set clock on the serial interface , Also the config on the B router can't be the same if you are providing clock on the B router , Does the B router have a DTE or a DCE cable attached ?

dal · ‎07-10-2003

It has the v.35 winchester cable. True - using external csu/dsu. Telcom said we would need to set the clock - for me, I thought with serial connection it did not matter.

deilert · ‎07-11-2003

Either the csu/dsu or the provider will have to supply clock , You can supply clock on a serial interface with a DCE cable attached , I wouls not recommend this for a long haul wide area connection . If you have access the the Csu's configure one to provide clock and the other to look for clock from the network.

dal · ‎07-11-2003

I am now in the process of setting to default configuration on both. I will put each on it's own subnet and see what happens. Will let you know.

dal · ‎07-11-2003

take a look at the following config. I reset both router to defaults (erased) and started from scratch. Router "A" is now on 192.168.0.21 and Router "B" 192.168.10.22 - each on their own subnets. The s0/0 line protocol still toggles up/down about every 10 seconds - toggling faster than before, but still not remaining up. HDLC on both ends. I have called the telecom - "they are investigating", but state everything appears fine from their site. Thanks

sh config

Using 786 out of 29688 bytes

!

version 12.2

service timestamps debug uptime

service timestamps log uptime

service password-xxx!

hostname CiscoA

!

enable password xxxx

!

memory-size iomem 25

ip subnet-zero

no ip domain lookup

!

interface FastEthernet0/0

description connected to EthernetLAN_1

ip address 192.168.0.21 255.255.255.0

no keepalive

speed auto

!

interface Serial0/0

description connected to CiscoB

ip unnumbered FastEthernet0/0

no logging event link-status

!

router rip

version 2

network 192.168.0.0

no auto-summary

!

ip classless

no ip http server

!

snmp-server community public RO

snmp-server enable traps tty

!

line con 0

exec-timeout 0 0

password xxx

login

line aux 0

line vty 0 4

password xxxx

login

!

end

*****************************************

CiscoA#sh interface fastethernet0/0

FastEthernet0/0 is up, line protocol is up

Hardware is PQUICC_FEC, address is 000b.466b.3bf0 (bia 000b.466b.3bf0)

Description: connected to EthernetLAN_1

Internet address is 192.168.0.21/24

MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive not set

Full-duplex, 100Mb/s, 100BaseTX/FX

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:02, output 00:00:19, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue :0/40 (size/max)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

30 packets input, 4027 bytes

Received 30 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog

0 input packets with dribble condition detected

7 packets output, 1625 bytes, 0 underruns

3 output errors, 0 collisions, 3 interface resets

0 babbles, 0 late collision, 0 deferred

3 lost carrier, 0 no carrier

0 output buffer failures, 0 output buffers swapped out

******************************************

CiscoA#sh int s0/0

Serial0/0 is up, line protocol is up

Hardware is PowerQUICC Serial

Description: connected to CiscoB

Interface is unnumbered. Using address of FastEthernet0/0 (192.168.0.21)

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

reliability 247/255, txload 1/255, rxload 1/255

Encapsulation HDLC, loopback not set

Keepalive set (10 sec)

Last input 00:00:04, output 00:00:03, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: weighted fair

Output queue: 0/1000/64/0 (size/max total/threshold/drops)

Conversations 0/2/256 (active/max active/max total)

Reserved Conversations 0/0 (allocated/max allocated)

Available Bandwidth 1158 kilobits/sec

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

21 packets input, 504 bytes, 0 no buffer

Received 21 broadcasts, 0 runts, 0 giants, 0 throttles

9 input errors, 0 CRC, 9 frame, 0 overrun, 0 ignored, 0 abort

63 packets output, 8512 bytes, 0 underruns

0 output errors, 0 collisions, 12 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions

DCD=up DSR=up DTR=up RTS=up CTS=up

CiscoA#

deilert · ‎07-11-2003

the config looks ok , what about the B router config ? ALso did you find out who is providing clock ? "Find out from the telco . Also who owns the Csu's , like I said before either one of the cs's or the telco is going to have to supply clock.

dal · ‎07-29-2003

After weeks of telcom stating everything is ok on their end, we find out they have a bad v.35 jack on the host side. Plugged my config back in on both routers and they work. Thanks for hanging in there with me and helping out.