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IP helper and access-lists

Hi All

If i am forwarding dhcp broadcasts through a router with the IP helper address command, do I some how have to include this in an access-list or will they be passed regardless of what is in the access-list.

Regards

  • Other Network Infrastructure Subjects
1 REPLY
Silver

Re: IP helper and access-lists

If you do not allow udp (atleast the ports that you are wanting to forward) they should be blocked.

Example:

If an ACL denies specific UDP ports, make sure that it does not deny ports used to forward the broadcast traffic in question (such as port 67 for BOOTP transmissions or port 68 for BOOTP replies).

Enter explicit permit statements for those ports used to forward broadcasts that you want to have forwarded.

The following is an example of using a permit statement in an ACL:

C7750(config)#access-list 101

permit udp any any eq

Hope this helps,

Don

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