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DHCP issue with WS-C3560G-24PS

Hi ,

DHCP relay not working in switch WS-C3560G-24PS

image details -

c3560-ipservicesk9-mz.122-55.SE.bin

its working if i keep DHCP server in same vlan as user ., wireshark says DHCP offer packets are currupted and there is no client ip (0.0.0.0 0.0.0.0 ) .

shark.jpeg

Thanks 4 reply

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9 REPLIES
Purple

DHCP issue with WS-C3560G-24PS

Hi,

Could you post the wireshark capture file filtering only DHCP.

Provide sh run | s dhcp.

Also do a debug ip dhcp server events and debug ip dhcp server packets on the switch doing relay.

Regards.

Alain.

Don't forget to rate helpful posts.
New Member

DHCP issue with WS-C3560G-24PS

Hi saqar,

i hope u hv configured "ip helper-address" in all other vlan interfaces.

Thx

shehin.pm

DHCP issue with WS-C3560G-24PS

Hi Alain ,

Here is the capture attached .

Thanks 4 reply

----------------------

Purple

Re: DHCP issue with WS-C3560G-24PS

Hi,

I was talking about the modified pcap showing only dhcp not a screenshot.

Can you also picture your topology with HSRP, DHCP server, DHCP pools and provide output of sh run | be dhcp on the switch.

Where was the capture taken? where is located DHCP server, is it router, w2k3,linux?

Regards.

Alain.

Don't forget to rate helpful posts.

DHCP issue with WS-C3560G-24PS

Hi Alain ,

This is windows server , switch 3560 acting as relay .Before switch was working as IOS DHCP and now I want it to configure as relay agent only .

In same vlan its working fine but on diff vlans its not .

I m not able to attach wireshark capture here , not able to find option   what most i can say DHCP offer packet is currupt with 0.0.0.0 in client address .

please let me know if any thing you can suggest me .

Thanks 4 reply

------------------------

Purple

Re: DHCP issue with WS-C3560G-24PS

Hi,

provide a picture of topology and post running of the 3560 .

Just use the attached file at the bottom of window to attach pcap file.

Regards.

Alain.

Don't forget to rate helpful posts.

Re: DHCP issue with WS-C3560G-24PS

Hi Alain ,

            wireshark attached 4 during the issue .

           topology is simple as both server and clients connected on same switch which is working as relay between two vlans .

Thanks 4 ur early repluy

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Re: DHCP issue with WS-C3560G-24PS

foget to add - full config I m not able to past here but here is the vlan for which i did wireshark capture -

!

interface Vlan100

description <<< A_Corp >>>

ip vrf forwarding A_VRF

ip address 10.107.170.2 255.255.255.192

ip access-group A_Corp in

ip helper-address 10.107.170.228

no ip redirects

no ip unreachables

no ip proxy-arp

standby 100 ip 10.107.170.1

standby 100 timers 5 10

standby 100 preempt

standby 100 authentication md5 key-string 7 052D423960666E3039

!

Purple

DHCP issue with WS-C3560G-24PS

Hi,

I've never configured DHCP relay agent with vrf so I'll lab it up to see if this is the vrf which may be causing the problem.

Regards.

Alain

Don't forget to rate helpful posts.
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