2620XM Router, 2950 Switch and Cable Modem Help

[somachu]

I have a Cisco 2620XM Router with one FastEthernet port and a WIC-1DSU-T1. I also have a Cat2950 and a cable modem. I want to connect my cable modem to the router (and use as a firewall) and then to the switch for my home network. I can get FA 0/0 to work when I connect it to the cable modem or LAN but can't seem to get the serial0/0 to play with either connection. Currently I have teh cable modem (dhcp) connected to my fastethernet connection. Using this config I can't even ping the serial0/0 ip from the router!:

Building configuration...

Current configuration : 1789 bytes
!
version 12.2
service timestamps debug datetime
service timestamps log datetime
service password-encryption
!
hostname 2620XM
!
no logging buffered
logging rate-limit all 10000
logging console informational
logging monitor informational
aaa new-model
!
clock timezone EASTERN -5
clock summer-time EASTERN_DLST recurring 1 Sun Apr 2:00 4 Sun Oct 2:00
ip subnet-zero
!
!
ip domain-name test.com
ip dhcp ping packets 1
!
ip audit notify log
ip audit po max-events 100
ip dhcp-client network-discovery informs 2 discovers 0
!
no call rsvp-sync
!
!
!
!
!
!
!
!
interface FastEthernet0/0
description Cable Modem
ip address dhcp
ip nat outside
speed auto
full-duplex
!
interface Serial0/0
description Switch
ip address 10.100.1.254 255.255.255.0
ip nat inside
!
router rip
version 2
passive-interface FastEthernet0/0
network 10.0.0.0
no auto-summary
!
ip nat inside source list 1 interface Serial0/0 overload
ip classless
ip route profile
ip route 0.0.0.0 0.0.0.0 FastEthernet0/0
no ip http server
ip http access-class 1
ip http authentication local
!
access-list 1 permit 10.100.1.0 0.0.0.255
access-list 101 permit ip any any
!
snmp-server engineID local 0000000902000005323446C0
snmp-server community public RO
snmp-server community XXXXX RW
snmp-server enable traps snmp authentication linkdown linkup coldstart warmstart
snmp-server enable traps tty
snmp-server enable traps config
snmp-server enable traps entity
snmp-server enable traps frame-relay
snmp-server enable traps rtr
!
dial-peer cor custom
!
!
!
!
banner motd ^CCC Haven ^C
!
line con 0
password 7 000815
stopbits 1
line aux 0
transport input all
line vty 0 4
password 7 xxxxx
line vty 5 15
password 7 xxxxx
!
end

Does anyone have any suggestions?? Thanks

 

[jneiberger]

You will not be able to ping the IP address on your serial interface unless the link is up and configured correctly on both ends. Pings to local serial interfaces actually leave the router, traverse the link, and come back. Is your serial link UP/UP?

 

[somachu]

No Serial0/0 is down, down.

 

[JOAMON]

??? What exactly are you trying to connect the serial port to??? Sounds like you need another ethernet port to be able to connect to your switch.

 

[jneiberger]

I think he's just expecting it to be ping-able since it has an IP address and he took the ping failures to be an indication of a real problem.

I have the same question, though. What are you connecting the serial interface to?

 

[somachu]

Sorry for the newbie question. For some reason, I had it in my head that you could connect the Ethernet port on the cable modem to the wic t1 port if you did it correctly. I was given a 2620XM and wanted to set up a firewall. Currently I have Server 2003 running RAS and 2 nics but wanted to use the router so my server isn't as exposed. Any other suggestions on how to set this up? Maybe with configuring different vlans (one vlan that the cable modem and router is connected to and then route it to another vlan that the internal network is on…)???

 

[jneiberger]

You definitely cannot connect an Ethernet interface to a serial interface and expect it to work, even if the physical connectors are the same. T1 and Ethernet are very different.

As you suggest, you may be able to do what is called one-armed routing with VLANs if your cable modem supports 802.1q trunking.