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New Member

no ip forward-protocol udp

We have the IP-helper statements on our VLAN interfaces of the 4507 core, configured for DHCP; our "dhcp" server is also our DNS/active directory server. Also in our global config, we have "no ip forward-protocol udp netbios-ns" and

"no ip forward-protocol udp netbios-dgm" configured. My question is, when there is a netbios request sent (to broadcast from a client) to find an internal server, and these "no ip forward-protocol" statements are in there....where does this packet get sent? or is it just dropped?

And could these statements (being in our config) be causing some of the response time issues when clients are trying to reach these (named) servers? Thanks for any help.

3 REPLIES

Re: no ip forward-protocol udp

no ip forward-protocol udp netbios-ns

no ip forward-protocol udp netbios-dgm

The above commands will drop UDP NetBIOS datagrams packets and UDP NetBIOS name query packets that are sent as well.

IP-helper statement will work if ip forward-protocol udp bootpc is turn on.

New Member

Re: no ip forward-protocol udp

So if our internal clients are trying to find shares on named servers, those packets being sent will be dropped....

Perhaps this is the reason why there is such a "lag" in trying to connect to these servers? These packets are sent and dropped, but perhaps other packets (on different UDP ports) are attmepted, and a successful match is made? I'm thinking we may have to take those commands out of the globabl config.

Re: no ip forward-protocol udp

I have listed some of protocols you can turn off. make sure the ones you need are turn on.

no ip forward-protocol udp biff

no ip forward-protocol udp bootps

no ip forward-protocol udp discard

no ip forward-protocol udp dnsix

no ip forward-protocol udp domain

no ip forward-protocol udp echo

no ip forward-protocol udp isakmp

no ip forward-protocol udp mobile-ip

no ip forward-protocol udp nameserver

no ip forward-protocol udp netbios-dgm

no ip forward-protocol udp netbios-ns

no ip forward-protocol udp netbios-ss

no ip forward-protocol udp non500-isakmp

no ip forward-protocol udp ntp

no ip forward-protocol udp pim-auto-rp

no ip forward-protocol udp rip

no ip forward-protocol udp snmp

no ip forward-protocol udp snmptrap

no ip forward-protocol udp sunrpc

no ip forward-protocol udp syslog

no ip forward-protocol udp tacacs

no ip forward-protocol udp talk

no ip forward-protocol udp tftp

no ip forward-protocol udp time

no ip forward-protocol udp who

no ip forward-protocol udp xdmcp

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