11-29-2006 12:56 AM - edited 03-05-2019 01:04 PM
I have two routers on my lan, both with the same function: bootp relay.
Both have exact the same config:
Router1 (C1720):
---
Current configuration:
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname DHCPRelay_tst2_C1720
!
enable password test
!
memory-size iomem 25
ip subnet-zero
no ip domain-lookup
!
!
!
!
interface BRI0
no ip address
no ip directed-broadcast
shutdown
!
interface FastEthernet0
ip address 10.32.214.163 255.255.255.0
ip helper-address 192.168.205.30
no ip directed-broadcast
!
router eigrp 1
network 10.0.0.0
!
router rip
network 10.0.0.0
!
ip classless
!
!
line con 0
password test
login
transport input none
line aux 0
line vty 0 4
password test
login
!
no scheduler allocate
end
---
Router2 (C1601):
---Current configuration:
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname DHCPRelay_tst1_C1601R
!
enable password test
!
ip subnet-zero
no ip domain-lookup
!
!
!
interface Ethernet0
ip address 10.32.214.164 255.255.255.0
ip helper-address 192.168.205.30
no ip directed-broadcast
!
interface Serial0
no ip address
no ip directed-broadcast
shutdown
!
router eigrp 1
network 10.0.0.0
!
router rip
network 10.0.0.0
!
ip classless
!
!
line con 0
password test
login
transport input none
line vty 0 4
password test
login
!
end
---
Problem: when a client request an IP, both routers relay the request to the DHCP server, but on the DHCPserverLAN, only the request from the 1st router is received. Both routers have a correct route to that server, and no firewalls are in between.
I notice the following however:
- the original DHCP discovery request from the client is a broadcast with soruceport 68 to destport 67 - seems normal.
- router 1 sends to the DHCPserver using sourceport 67 to destport 67
- router 2 sends to the DHCPserver using sourceport 68 to destport 67
So both routers have a different behaviour - anybody know why?
And why doens't the 2nd DHCP disc relay request doens't get through to the DHCPserver?
thanks!!!!
11-29-2006 04:14 AM
are u able to ping DHCP server 192.168.205.30 from 2nd router using source IP 10.32.214.164 ?
11-29-2006 05:27 AM
yes, that is no problem.
I find it strange that both routers use a different sourceport (67 vs. 68) to relay the discovery packet.
I don't know if this is the source of my problem though.
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