Hi,
My problem is the next:
I wanted to change our DHCP relay device (Linksys WRT54GL with OpenWRT) to Cisco 1751 router. There are in the same LAN.
Far from that LAN there is a remote LAN where the DHCP+TFTP sever resides.DHCP relay worked with Linksys so routing is working between the clients and server.
When I configured c1751 the DHCP packets not reach the DHCP server!
The relay router not on the path to the remote LAN (serial interfaces are connected to other WAN directions), but the target LAN reachable.
Of course I disabled DHCP relay function on Linksys. ;-)
c1751's IOS: 12.4
The config: (relevant command only)
ip dhcp relay information option
ip dhcp relay information trust-all
...
interface FastEthernet0/0
ip address 192.168.1.240 255.255.255.0
ip helper-address 192.168.52.30
ip directed-broadcast
...
no ip forward-protocol nd
no ip forward-protocol udp domain
no ip forward-protocol udp time
no ip forward-protocol udp netbios-ns
no ip forward-protocol udp netbios-dgm
no ip forward-protocol udp tacacs
ip forward-protocol udp bootpc
...
access-list 150 permit udp host 192.168.1.240 host 192.168.52.30
...
K_dgr#sh deb
Generic IP:
IP packet debugging is on for access list 150
DHCP server packet debugging is on.
DHCPC:
DHCP client activity debugging is on
Dec 1 11:52:27: DHCPD: setting giaddr to 192.168.1.240.
Dec 1 11:52:27: DHCPD: adding relay information option.
Dec 1 11:52:27: IP: s=192.168.1.240 (local), d=192.168.52.30 (FastEthernet0/0), len 362, sending
Dec 1 11:52:27: IP: s=192.168.1.240 (local), d=192.168.52.30 (FastEthernet0/0), len 362, encapsulation failed
Dec 1 11:52:27: DHCPD: BOOTREQUEST from 0100.0ea6.1e62.32 forwarded to 192.168.52.30.
Dec 1 11:52:31: DHCPD: setting giaddr to 192.168.1.240.
Dec 1 11:52:31: DHCPD: adding relay information option.
Dec 1 11:52:31: IP: s=192.168.1.240 (local), d=192.168.52.30 (FastEthernet0/0), len 362, sending
Dec 1 11:52:31: IP: s=192.168.1.240 (local), d=192.168.52.30 (FastEthernet0/0), len 362, encapsulation failed
Dec 1 11:52:31: DHCPD: BOOTREQUEST from 0100.0ea6.1e62.32 forwarded to 192.168.52.30.
I've got no ideas what could be the problem!
What is 'encap. failed'? And the sending? If it was sent why can't my DHCP see tha packets?
Between the relay agent (c1751) and DHCP+TFTP server thera are some non Cisco routers (3Com+Proteon) without any DHCP or TFTP config.
TFTP doesn't work, either.
It is reach the server, server send the answer back and thats all. Timeout ...
Please, help me! I dislike these kind of non routeable protocols ...
TIA
