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New Member

SF300 dhcp relay

Hi all, i have allready read a lot of information, but steal don't know ther answer, please help

DHCP server is allocated on 2911 router (c2900-universalk9-mz.SPA.152-1.T.bin)

on SF300 (l3 mode):

interface vlan 8 -

interface vlan 18 -

interface vlan 4 - get ip with DHCP option

to port 3 (access vlan 18) is connected device with get ip with DHCP option

on 2911 there is access-list, that tells us that some device's from vlan 8 all the time are sending request on port 137 and 138 but not from others vlan's

Nov 14 11:50:10: %SEC-6-IPACCESSLOGP: list test permitted udp ->, 1 packet 

Nov 14 11:50:12: %SEC-6-IPACCESSLOGP: list test permitted udp ->, 1 packet 

screenshots are atteched

DHCP relay in enabled (tried with and without option 82)

dhcp server ip address ( is nearest interface of 2911 (is accessable from each vlan)

to DHCP relay interfaces are added vlan 18 and vlan 4

in UDP relay there are port's 137 and 138 added for source ip interface vlan 8, vlan 18 and ALL

Everyone's tags (4)
New Member

SF300 dhcp relay

addition about routing:

default gateway is (as you can see, it belongs to vlan 8)