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New Member

Unable to forward DHCP request via ip helper-address

Currently, I am configuring a 6509 switch with Native IOS code version [12.1(12c)E2] [image name: c6msfc2-boot-mz.121-8a.EX]. But, I found that ip helper-address is not able to forward DHCP request. The config is simple and works fine in many routers that I worked before.

Also

Here is the int config

ip address 129.39.127.33 255.255.255.224

ip access-group 110 in

ip access-group 120 out

ip helper-address 129.39.126.186

no ip redirects

no ip unreachables

no ip proxy-arp

ip route-cache policy

duplex full

speed 100

no cdp enable

When I put a access list to check in-out packet, I found that no packet with udp 67/ 68 to pass through gateway int. Only 0.0.0.0 src packet to broadcast address is used.

*Apr 15 16:56:00 HKT: %SEC-6-IPACCESSLOGP: list 110 permitted udp 0.0.0.0(0) -> 255.255.255.255(0), 1 packet

*Apr 15 16:58:28 HKT: %SEC-6-IPACCESSLOGP: list 110 permitted udp 169.254.101.125(0) -> 169.254.255.255(0), 1 packet

2 REPLIES
Bronze

Re: Unable to forward DHCP request via ip helper-address

Calvin,

Please post ACLs 110 and 120.

Mark

New Member

Re: Unable to forward DHCP request via ip helper-address

The problem has been solved to config FW rules. It is not related to router/ switch config

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