Cisco 2621 serial problems.

[DavidCCNAacad]

I'm trying to get 6 2621 routers up and running via Serial ports, problem is I can get the ethernet to work, but the serial won't do anything. Here's my configuration:
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname LAB-A
!
enable secret 5 $1$BtAE$nYRTbRby8D1I7516teFnj/
enable password ciscoen
!
ip subnet-zero
!
!
!
!
!
!
interface FastEthernet0/0
ip address 192.5.5.1 255.255.255.0
duplex auto
speed auto
!
interface Serial0/0
physical-layer async
no ip address
encapsulation slip
async default routing
async mode dedicated
!
interface FastEthernet0/1
ip address 205.7.5.1 255.255.255.0
duplex auto
speed auto
!
interface Serial0/1
no ip address
shutdown
!
router rip
version 2
network 20.0.0.0
network 192.5.5.0
network 199.6.13.0
network 201.100.11.0
network 205.7.5.0
no auto-summary
!
ip classless
no ip http server
!
snmp-server community public RO
snmp-server enable traps tty
!
line con 0
line 1
flush-at-activation
line aux 0
line vty 0 4
login
!
end

 

[DavidCCNAacad]

I changed my encapsulation to PPP now it's going from down to UP, which is good, but then it goes to down again. How cna I make it stablize?

 

[baddos]

How are you connecting these routers together? A serial cable or going through a frame relay switch?

 

[DavidCCNAacad]

serial DCE/DTE cables.

 

[baddos]

Are you setting the clock rate on one end?

 

[DavidCCNAacad]

hm.. I'll have to try that. It should be automatically set by the router at 7200

 

[jimmyzz]

David,

The basic setup for connecting serial interfaces back-to-back, simply put an ip on each serial interface and set the clockrate on one of the routers as outlined by baddos.

example.
R1
int serial0/0
ip address x.x.x.1 <mask>
no shutdown

R2
int serial0/0
ip address x.x.x.2 <mask>
no shutdown
clockrate 2000000

Remove the encapsulation slip and async commands. You should be able to ping each remote serial interfaces from the routers. You can modify the config a to simulate FR back-to-back. Check the web for FR config samples.

JimmyZ

 

[DavidCCNAacad]

Thanks, I'll try that tomarrow when I get to school. does encapsulation need to be SLIP or PPP?

 

[Syty]

You an use PPP, but the default HDLC will work

int serial x/x
no encap

--or--

encap HDLC

just make sure that both routers agree on encapsulation, and that the clock rate is put on the DCE connection....