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DHCP server problem

elecorbalan
Level 1
Level 1

Hello, I try to establish an external DHCP server for a remote server VPN. With a capture, I can see packets going to DHCP server but I can't see any response from DHCP server.

How can I see response incoming in from DHCP server on my capture?

tunnel-group TunelVPN general-attributes

default-group-policy TunelVPN

dhcp-server 10.0.0.4

The capture is

30: 18:18:52.662380 10.0.0.22.68 > 10.0.0.4.67: udp 548

31: 18:18:55.659694 10.0.0.22.68 > 10.0.0.4.67: udp 548

32: 18:18:59.659694 10.0.0.22.68 > 10.0.0.4.67: udp 548

33: 18:19:04.659694 10.0.0.22.68 > 10.0.0.4.67: udp 548

5 Replies 5

elecorbalan
Level 1
Level 1

I think I should get a broadcast like this:

34: 18:20:43.277375 10.0.0.2.138 > 10.0.0.255.138: udp 239

35: 18:20:43.277451 10.0.0.2.138 > 10.0.0.255.138: udp 208

36: 18:20:46.309386 10.0.0.2.138 > 10.0.0.255.138: udp 239

37: 18:20:46.309447 10.0.0.2.138 > 10.0.0.255.138: udp 208

38: 18:24:49.758871 10.0.0.2.138 > 10.0.0.255.138: udp 239

39: 18:24:49.758948 10.0.0.2.138 > 10.0.0.255.138: udp 208

are you using the ip helper command on your firewall?

with IPsec, you can only turn a broadcast into a directional

broadcast with the ip helper

address command on the inside of your source.

There is no ip helper command on ASA

Thanks

then try configuring it because the dhcp request is a broadcast and it wont reach the other site without the directed broadcast

Finally,

It is right to send a unicast.

But I can't receive any response from the server.

Maybe I have to configure a DHCP relay, do you know if it is needed to configure a DHCP relay? Because I have to unconfigure DHCP server from VPN tunnel-group to configure DHCP relay.