Hello,
I have this scenario as part of a test rig:
VM Guest 1 <--> vSwitch <--> VM Guest 2 (bridging) <--> vSwitch <--> VM Guest 3
VM Guest 1 and 3 are set-up with a VLAN trunk (with VLAN ID 10). Both vSwitches are configured to allow ALL VLANS (VLAN 4095), which to my understanding would prevent any VLAN tags from being striped.
When i try and ping VM Guest 3 from VM Guest 1, i get no response. Upon further investigation, I found that packets are leaving VM Guest 1 with a VLAN tag, and arriving at VM Guest 2 without a VLAN tag. So even though the vSwitch is configured to allow ALL VLANs (VGT mode with VLAN ID 4095), it's clear that it is still stripping the VLAN header off.
Packets leaving VM Guest 1:
# tcpdump -i eth0 -n -e host 10.18.0.100
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
13:41:59.254684 00:50:56:bb:69:4b > ff:ff:ff:ff:ff:ff, ethertype 802.1Q (0x8100), length 46: vlan 10, p 0, ethertype ARP, Request who-has 10.18.0.100 tell 10.18.1.100, length 28
Packets arriving at VM Guest 2:
# tcpdump -i eth2 -n -e host 10.18.0.100
tcpdump: WARNING: eth2: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth2, link-type EN10MB (Ethernet), capture size 65535 bytes
05:42:35.254785 00:50:56:bb:69:4b > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 60: Request who-has 10.18.0.100 tell 10.18.1.100, length 46
Does anyone have any idea what's going on here?
Regards,
John