DHCP on SVI Issue

[Ezequiel Pineda]

Hi @Aliki

I am facing an issue when trying to accomplish something i assumed was fairly simple.

I am configuring a VPS cluster for Containers and Virtual Machines with Proxmox.

The scenario is the following:

4 Servers sharing the 185.128.43.16/29 network. Each host is assigned an IP on this range.

185.191.239.0/26 as a "Secondary Address" on this vlan.

I have deployed a Windows server 2012 Virtual Machine acting as the DHCP Server for the VM's.

The idea is to configure the Containers and Virtual Machines to obtain IP's via DHCP.

Here is the thing, all the servers are on the same vlan, no ACL is configured other than to allow such mentioned subnets. The issue is this.

If both, the DHCP Server is on the same server as the VM Client, then the dhcp request/offer takes place without issues.

If the VM client is on a different Server, even though they are on the same vlan, nothing happens.

Im trying to think what could be the issue as it seems like its a networking issue.

Thanks,

Ezequiel Pineda

[Deepak Kumar]

Hi,

Is the EtherChannel in Access mode or trunk mode? If it is in access mode then try with portfast. 

Regards,

Deepak Kumar 

[Ezequiel Pineda]

Hi Deepak,

Here is my config.

SVI on L3 Switch

interface Vlan3807
 description CUSTOM VLAN PROXMOX CLOUD
 ip address 185.191.239.1 255.255.255.192 secondary
 ip address 10.99.99.1 255.255.255.0 secondary
 ip address 185.128.43.17 255.255.255.248
 no ip redirects
 ip route-cache same-interface
 ipv6 address 2A03:9A60:F5::1/48
end

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Then, the config on the Distribution Switches

SRV1C1S1#sho run int gi1/0/34
Building configuration...

Current configuration : 201 bytes
!
interface GigabitEthernet1/0/34
 switchport access vlan 3807
 switchport mode access
 switchport nonegotiate
 ip access-group INTERNALDEFENSE in
 speed 1000
 duplex full
 spanning-tree portfast
end

SRV1C1S1#

If I assign any IP of the 185.191.239.0/26 network to any VM on any container, it works just fine.

Its DHCP the issue at the moment, not sure why though.

Ezequiel Pineda

[Ezequiel Pineda]

Deepak,

As it turns out, the issue was the **bleep** ACL.

I removed it just to test and it works as expected now. I will look into it and see why its blocking it.

Thanks for the time.

Ezequiel Pineda

[Deepak Kumar]

Hi,

You mentioned about no acl.

Regards,

Deepak Kumar

[Ezequiel Pineda]

Yeah, i thought i had removed it.