From: kuldip singh (dipa.singh@gmail.com)
Date: Wed Oct 24 2007 - 12:45:17 ART
Hi,
It seems like I can't get the native VLAN to work. As shown below
I have two sub-interfaces configured on R4, vlan 10 and vlan 555. if the
sub-interfaces are configured as trunk ports and the switchport is
configured as trunk port I can ping the 10.10.10.201 and 131.10.160.5 (R5
connected to switch 3). If I change the sub-interface on R4 (e0/1.10 ) to
mark vlan 10 as native and change the config on switch 4 to mark the vlan 10
as native. I can't ping 10.10.10.201 address, but I can still ping vlan 555
ok.
Can somebody spot the issue. (This is from one of the NMC documents).
Thanks
R4: (R4 connected to Switch 4)
interface Ethernet0/1
no ip address
half-duplex
!
interface Ethernet0/1.10
encapsulation dot1Q 10
ip address 10.10.10.1 255.255.255.0
no snmp trap link-status
!
interface Ethernet0/1.555
encapsulation dot1Q 555
ip address 131.10.160.1 255.255.255.0
no snmp trap link-status
SW4:
interface FastEthernet0/4
switchport trunk encapsulation dot1q
switchport mode trunk
interface Vlan10
ip address 10.10.10.201 255.255.255.0
SW3;
interface FastEthernet0/5
switchport access vlan 555
switchport mode access
Ping from R4;
Rack9SW4#ping 10.10.10.201
Sending 1, 100-byte ICMP Echos to 10.10.10.201, timeout is 2 seconds:
!
Success rate is 100 percent (1/1), round-trip min/avg/max = 4/4/4 ms
Rack9SW4#
Sending 1, 100-byte ICMP Echos to 131.10.160.5, timeout is 2 seconds:
!
Success rate is 100 percent (1/1), round-trip min/avg/max = 1/1/1 ms
Rack9SW4#
Now change the config on R4 and SW4 to make VLAN 10 native.
R4:
interface Ethernet0/1.10
encapsulation dot1Q 10 native
ip address 10.10.10.1 255.255.255.0
no snmp trap link-status
end
SW4:
interface FastEthernet0/4
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport mode trunk
end
Ping from R4:
Rack9R4#ping 10.10.10.201
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.10.10.201, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
Rack9R4#
Rack9R4#ping 131.10.160.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 131.10.160.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/3/4 ms
Rack9R4#
debug on the route R4 indicates encapsulation failure when vlan 10 is made
native.
Oct 24 08:34:38.682: IP: s=10.10.10.1 (local), d=10.10.10.201(Ethernet0/1.10),
len 100, sending
Oct 24 08:34:38.686: IP: s=10.10.10.1 (local), d=10.10.10.201(Ethernet0/1.10),
len 100, encapsulation failed.
Oct 24 08:34:40.682: IP: tableid=0, s=10.10.10.1 (local), d=10.10.10.201(Ethern
et0/1.10), routed via RIB
Oct 24 08:34:40.682: IP: s=10.10.10.1 (local), d=10.10.10.201(Ethernet0/1.10),
len 100, sending
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