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Problems enabling DHCP snooping on WS-C3750G

Posted on 2010-11-24
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Last Modified: 2012-05-10
I'm having problems enabling dhcp snooping on a Core switch(WS-C3750G-12S-S). The DHCP server (Win 2003 std.) is connected to port 2/0/13, and I'm testing with a VMware client connected to the switch (vlan5).

NyCoreswitch#sh ip dhcp snooping
Switch DHCP snooping is enabled.
DHCP snooping is configured on following VLANs:
4-6,9-10,44,340
Insertion of option 82 is disabled
   circuit-id format: vlan-mod-port
    remote-id format: MAC
Option 82 on untrusted port is not allowed
Verification of hwaddr field is enabled
Interface                    Trusted     Rate limit (pps)
------------------------     -------     ----------------
...
GigabitEthernet2/0/13        yes         unlimited
...

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What am I missing?

Thanks!
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Question by:Spanjis
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Expert Comment

by:lrmoore
ID: 34210105
Snooping is enabled, and port 2/0/13 is trusted. This is the way it works. It will trust dhcp server on this port.
I assume that it is the only trusted port? If yes, then what is the issue?
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Author Comment

by:Spanjis
ID: 34214530
Hi Irmoore,

This is the only trusted port right now.

I've double-checked the DHCP-server port.

ipconfig-all tells me that this is the DHCP-server:
DHCP-server . . . . . . . . . . . : 172.18.4.53

So the DHCP-server is connected to port Gi2/0/13:
NyCoreswitch#sh arp | include 172.18.4.53
Internet  172.18.4.53             0   000b.cd2f.9afe  ARPA   Vlan4
NyCoreswitch#sh mac-address-table | include 000b.cd2f.9afe
   4    000b.cd2f.9afe    DYNAMIC     Gi2/0/13

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But when i enable dhcp-snooping, and run ipconfig /release /renew the client don't get an IP-address.
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Accepted Solution

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Spanjis earned 0 total points
ID: 34240630
Embarrassing, the DHCP server had 2 NIC.
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Author Closing Comment

by:Spanjis
ID: 34276736
debug ip dhcp snooping did the trick :) I then found out the DHCP server had 2 NIC's.
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