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I'm trying to configure a new subnet for my users. DHCP is configured on the switch SW1.

The topology looks like this : SW1 <===> SW2 <===> PC

There is an etherchannel + trunk link between SW1 and SW2.

For whatever reasons, I cannot ping the PC. It gets an IP just fine.

Here is my configuration on SW1:

ip dhcp class rangeuser
ip dhcp pool UsersLAN
network 10.239.146.0 255.255.255.0
domain-anme xx.com
dns-server 172.30.184.5 172.30.184.4
default-router 10.239.146.1
lease 0 2
class rangeuser
 address range 10.239.146.10 10.239.146.250
  address 10.239.146.82 client-id 0114.b31f.17c5.a7

int po24
switchport mode trunk

int vlan11
 ip address 10.239.146.5 255.255.255.0

And on SW2:

 int po24
  switchport mode trunk

 int gi2/0/41
  switchport access vlan 11
  switchport mode access
  switchport voice vlan 30
  spanning-tree portfast
  spanning-tree bpduguard enable

Show ip dhcp binding displays the lease. But when I try to ping using source interface vlan 11, it simply does not work. If I put back the access port into the old user vlan (vlan 10), then I can ping just fine with my switch.

What's going on here ?

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2
  • Your question is really too broad to answer. Please include the full switch configurations. There are other configurations that may affect this. For example, did you create the new VLAN on the switches with the global vlan command (not the interface vlan command)?
    – Ron Maupin ♦
    Sep 23, 2019 at 14:11
  • Can you ping the PC at all? Possibly, its local firewall doesn't allow ICMP echo requests.
    – Zac67 ♦
    Sep 23, 2019 at 14:31

1 Answer 1

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I figured it out eventually.

When a computer has joined a domain, it tries to contact its domain controller after getting an IP. In Vlan 10, it was able to do so successfully, and would categorize the network as a "Domain network". The Windows Firewall was disabled for domain networks.

When in Vlan11, the subnet was not allowed to contact the domain controller because it was dropped on a Firewall along the way. This resulted in the network being categorized as a "Public network", where the Windows firewall was enabled.

After opening the network flows, it started working.

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