I have a DHCP relay configuration - Switchs in Core and Edge topology and i´m trying to figure out what the previous sysadmin did:
I have 8 * HP E2620-48-PoEP Switch(J9627A) as EDGE Switchs
I have 2 * HP A5500-48G EI, stacked, as CORE Switchs
I Have several VLANs, and a Windows DHCP Server configured to lease IP for all VLANs and is working perfectly
But recently, i found something weird in the configs
1) I found ip helper configs pointing to my DHCP Server on all EDGE switches (that ones that do not route, the "CORE" switchs do the routing/layer 3 processing), so i think maybe it´s an error from the past, am I right?
2) The config is on the SAME VLAN the DHCP Server is running, so, again, looks like a ghost from the past or the crazyness of a sysadmin,, am I right?
A sample:
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vlan 800
name "LEGACY"
untagged 9,46
tagged 38,Trk1
no ip address
ip helper-address 1.2.3.4
exit
no dhcp config-file-update
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In the "CORE" Switch, i have the config, i´m supposed to be right:
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dhcp relay server-group 0 ip 1.2.3.4
interface Vlan-interface107
ip address 10.121.131.1 255.255.255.0
dhcp select relay
dhcp relay server-select 0
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But even in the "CORE" Switch, again, another wierd stuff (at least to me): why does SOME VLANs have the udp-helper configurarion? The DHCP is also a DNS/NTP Server, but i can´t understand why is that, the documentation is crystal clear about not using udp helper for DCHP purposes, so i have no idea on why is that
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interface Vlan-interface700
ip address 10.121.62.1 255.255.255.0
dhcp select relay
dhcp relay server-select 0
udp-helper server 1.2.3.4
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