RE: native vlan

From: Antonio Soares (amsoares@netcabo.pt)
Date: Wed Oct 24 2007 - 20:06:01 ART


This is a know issue with the older 10Mbps NICs. Move the IP Address that
corresponds to the native vlan to the main interface and test again.

Regards,

Antonio Soares
CCIE #18473 (R&S),CCNP,CCIP,JNCIA-ER
http://pwp.netcabo.pt/amsoares/

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
kuldip singh
Sent: quarta-feira, 24 de Outubro de 2007 16:45
To: Group Study
Subject: native vlan

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



This archive was generated by hypermail 2.1.4 : Fri Nov 16 2007 - 13:11:18 ART