I use a 3550 L2/L3 switch and I need to use a remote dhcp server.
I configured it on my router but it didn't work.
So I prepared a testing router with a very simple configuration but again I had problem. The request starts regulary, the router forward the request correctly, the dhcp server offers the ip address but the router answer back to the dhcp server that the his port 68 was unreachable.
Where I did wrong?
TIA.
Follows the configuration and some debug output.. test# sh ver test#sh ver
Cisco IOS Software, C3550 Software (C3550-IPSERVICESK9-M), Version
12.2(25)SEB4, RELEASE SOFTWARE (fc1) Copyright (c) 1986-2005 by Cisco Systems, Inc. Compiled Tue 30-Aug-05 17:35 by yenanh
ROM: Bootstrap program is C3550 boot loader ..
test#sh running-config Building configuration...
Current configuration : 2385 bytes ! version 12.2 no service pad service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname test ! enable secret ***************** enable password *************** ! no aaa new-model ip subnet-zero ip routing ! ! ! ! ! ! no file verify auto spanning-tree mode pvst spanning-tree extend system-id ! vlan internal allocation policy ascending ! ! interface FastEthernet0/1 no switchport ip address 172.28.48.254 255.255.255.0 ! interface FastEthernet0/2 no switchport ip address 172.28.33.254 255.255.255.0 ip helper-address 172.28.48.77 ! interface FastEthernet0/3 switchport mode dynamic desirable !
.....
snmp-server community cce RO ! control-plane ! ! line con 0 exec-timeout 0 0 line vty 0 4 password ********* login line vty 5 15 password ********* login ! ! end
test#
debug ip udp debug ip icmp
test#
17:42:20: UDP: rcvd src=0.0.0.0(68), dst=255.255.255.255(67), length=308
17:42:20: UDP: sent src=172.28.33.254(67), dst=172.28.48.77(67), length=308
17:42:20: UDP: rcvd src=172.28.48.77(67), dst=172.28.33.254(68), length=308
17:42:20: ICMP: dst (172.28.33.254) port unreachable sent to 172.28.48.77
17:42:22: UDP: rcvd src=0.0.0.0(68), dst=255.255.255.255(67), length=308
17:42:22: UDP: sent src=172.28.33.254(67), dst=172.28.48.77(67), length=308
17:42:22: UDP: rcvd src=172.28.48.77(67), dst=172.28.33.254(68), length=308
17:42:24: UDP: rcvd src=0.0.0.0(68), dst=255.255.255.255(67), length=308
17:42:24: UDP: sent src=172.28.33.254(67), dst=172.28.48.77(67), length=308
17:42:24: UDP: rcvd src=172.28.48.77(67), dst=172.28.33.254(68), length=308
17:42:24: ICMP: dst (172.28.33.254) port unreachable sent to 172.28.48.77