Routing DHCP

[lanspark]

I seem to be having trouble getting this router to forward DHCP to a remote network over frame. I have enabled the helper address on the ethernet interface. (Which usually does the trick) For some reason it just wont work. Any ideas?

Using 1274 out of 29688 bytes
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname ********
!
no logging console
enable secret 5 **********************
!
username ********* password **********
!
!
!
!
memory-size iomem 25
ip subnet-zero
!
!
!
!
interface Serial0
ip address 192.168.254.4 255.255.255.0
no ip directed-broadcast
encapsulation frame-relay IETF
no fair-queue
service-module t1 timeslots 1-8
frame-relay interface-dlci 100
frame-relay lmi-type ansi
!
interface FastEthernet0
description Connected to Corporate Network
ip address 192.168.100.10 255.255.255.0
ip helper-address 192.168.0.5
no ip directed-broadcast
half-duplex
!
router eigrp 10
network 192.168.100.0
network 192.168.254.0
no auto-summary
!
router rip
redistribute connected
redistribute static
network 192.168.100.0
network 192.168.254.0
no auto-summary
!
ip classless
no ip forward-protocol udp netbios-ns
no ip forward-protocol udp netbios-dgm
ip route 0.0.0.0 0.0.0.0 192.168.254.1
no ip http server
!
!
line con 0
login local
transport input none
line aux 0
login local
modem InOut
transport input all
speed 115200
flowcontrol hardware
line vty 0 4
login local
!
no scheduler allocate
end

[dinowuff]

Only time I've ever screwed up DHCP over Frame is when I had one or more of the following blcked on one or both sides.


TFTP (port 69)
DNS (port 53)
Time (port 37)
TACACS (port 49)
BOOTP client (port 68)
BOOTP server (port 67)
NetBIOS name service (port 137)
NetBIOS datagram service (port 138)

[lanspark]

Originally posted here by dinowuff
Only time I've ever screwed up DHCP over Frame is when I had one or more of the following blcked on one or both sides.


TFTP (port 69)
DNS (port 53)
Time (port 37)
TACACS (port 49)
BOOTP client (port 68)
BOOTP server (port 67)
NetBIOS name service (port 137)
NetBIOS datagram service (port 138)

Blocking Netbios services shouldn't have any effect. I have to block them, or esle I get flooded with master browser requests. I have other routers setup with that configuration with no problem. Where this one differs from ther other routers that I manage, is the eigrp 10 section. I didn't set these up initialy so I'm not sure what purpose it serves. Is anyone familiar with eigrp and if it would affect DHCP?

[dinowuff]

Should have been more specific:

The ports listed I use for troubleshooting OPEN all then check. Just something I do.

Anyway There were Enhanced Interior Gateway Routing Protocol (EIGRP) Defects years ago - I think in the late 90's in almost all versions of the cisco IoS. So what version of IoS and are the versions the same on both routers? -

Also, Didn't see any IKE or IPSec settings. If You are using IPsec, the EIGRP setting would look something like this;

router eigrp 10
network 192.168.0 0.0.0.3
network 192.168.2.0
no auto-summary
no eigrp log-neighbor-changes

[lanspark]

It looks like the others are on 11.2 and this one is on 12.0. Hmm....

[dinowuff]

Products Affected
The Cisco IOS Software revisions below are affected by CSCdj60533 and CSCdj58676, except where noted.

Software Release Images Affected Resolution
11.2 All images 11.2(9.1) - 11.2(10), 11.2(10a) ** 11.2(11)
11.2P All images 11.2(9.1)P - 11.2(10)P, 11.2(10a)P **+ 11.2(10a)P1, 11.2(11)P
11.2BC All images 11.2(9.1)BC - 11.2(10)BC, 11.2(10a)BC ** 11.2(11)BC
11.2XA All images 11.2(9)XA & 11.2(9)XA1 N/A ++
11.1 * All images 11.1(15.1) - 11.1(15.5) 11.1(16)
11.1AA * All images 11.1(15.1)AA - 11.1(15.5)AA 11.1(16)AA
11.1CA * All images 11.1(15)CA - 11.1(15.5)CA 11.1(16)CA
11.1IA * All images 11.1(15)IA - 11.1(15.5)IA 11.1(16)IA

Here's the link: http://www.cisco.com/en/US/products/...80094457.shtml

I feel for you

[lanspark]

The thing is, the routers running 11.2 seem to be working fine. I'm handing out addresses to those networks with no problem. It's the router with 12.0 that I can't get to forward.

[dinowuff]

hummm - are you using eigrp on all interfaces?

[lanspark]

Apparently this is the only one with any reference to eigrp. I need to do my homework on what that exactly does. The others are connected in the exact same fashion. However, for some reason this one seems to have a more complicated config. I am hesitant to take anything out of it given there is no modem setup in that location in case it gets knocked off the frame. Here's an example of one that is forwarding DHCP without issue.

Using 895 out of 7506 bytes
!
version 11.2
no service password-encryption
no service udp-small-servers
no service tcp-small-servers
!
hostname ********
!
enable secret ***********
!
username ******** password *****
!
interface Ethernet0
ip address 192.168.20.254 255.255.255.0
ip helper-address 192.168.0.5
no ip directed-broadcast
!
interface Serial0
no ip address
shutdown
!
interface Serial1
description 512K Frame-Relay connection
ip address 192.168.254.3 255.255.255.0
encapsulation frame-relay IETF
service-module t1 timeslots 1-8
frame-relay interface-dlci 100
frame-relay lmi-type ansi
!
router rip
redistribute connected
network 192.168.20.0
network 192.168.254.0
!
no ip classless
no ip forward-protocol udp netbios-ns
no ip forward-protocol udp netbios-dgm
no logging console
snmp-server community public RO
!
line con 0
login local
line vty 0 4
login local
!
end

[dinowuff]

No prob -
Rem out the serial config lines for eigrp. Or look up the command line - However you want to edit your configuration.

Save the config - don't think you need to flash or reboot.

Anyway - however you decide to change, removing the eigrp setting will get you back up and running.