Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
Community Member

2611 DHCP problem?

I just tried re-programming our 2611 router to make use of it, since we just got a PIX 515E to work as our firewall, and everything looks ok, but for some reason, the outside interface won't pick up an IP address. I set it to DHCP, and when I type "show ip interface ethernet 0/1" it says address will be negotiated using DHCP. Any ideas? If anyone wants, I'll post the configuration.



Re: 2611 DHCP problem?

From what you say, it seems like everything is OK on your side.

Is the interface up? Where is the DHCP server located?

You may post the config to check.



Community Member

Re: 2611 DHCP problem?

The DHCP server that the router would be getting it's IP address on is on Optimum Online's (Cable Modem) system. Yes, the interface is up, and both sides show a link.

Also, If I wanted to, how would I remove the entire configuration to reset the IOS to factory defaults?

Here is the config:

Current configuration : 1637 bytes


version 12.2

no parser cache

no service single-slot-reload-enable

service timestamps debug uptime

service timestamps log uptime

service password-encryption


hostname southold


logging rate-limit console 10 except errors

enable secret 5

enable password 7


ip subnet-zero

no ip source-route



ip tcp synwait-time 5


ip inspect name firewall tcp

ip inspect name firewall ftp

ip inspect name firewall smtp

ip inspect name firewall udp

ip inspect name firewall fragment maximum 256 timeout 1

ip inspect name firewall vdolive

ip inspect name firewall realaudio

ip inspect name firewall http

ip inspect name firewall h323

ip inspect name firewall netshow

ip inspect name firewall rtsp

ip inspect name firewall sqlnet

ip inspect name firewall streamworks

ip inspect name firewall cuseeme

ip audit notify log

ip audit po max-events 100

no ip dhcp-client network-discovery




interface Ethernet0/0

description admin

ip address

ip nat inside



interface Ethernet0/1

description student_network

ip address dhcp

ip access-group 125 in

ip nat outside

ip inspect firewall out



ip nat inside source list 1 pool admin-student overload

ip classless

ip route Ethernet0/1

ip http server


access-list 1 permit

access-list 125 permit icmp any any

access-list 125 deny ip any any


line con 0

password 7

logging synchronous


line aux 0

password 7


line vty 0 4

password 7


line vty 5 15

password 7





Re: 2611 DHCP problem?

The reason is in your access-list 125 in. This blocks the DHCP packets.

Remove it. I also notice that you are running FW-software.

Besides, it looks as if telnet is open on the Internet, that is, once you get an IP on it. Please configure something like:

lin vty 0 15

ip access-class 1 in

This blocks telnet from the outside.

To clear the router:

write erase




CreatePlease to create content