From: Darby Weaver (darbyweaver@yahoo.com)
Date: Thu Oct 25 2007 - 01:50:48 ART
Thanks Brian,
I never realized this before. Since I upgraded my
primary rack and used to have some issues with native
VLANs - I may have had some trouble with this in the
past - come to think of it.
Good one.
--- Brian Dennis <bdennis@internetworkexpert.com>
wrote:
> On standard 10meg Ethernet interfaces the native
> VLAN must be 1.
>
> --
>
> Brian Dennis, CCIE4 #2210 (R&S/ISP-Dial/Security/SP)
> bdennis@internetworkexpert.com
>
> Internetwork Expert, Inc.
> http://www.InternetworkExpert.com
> Toll Free: 877-224-8987
> Direct: 775-852-3995 (Outside the US and Canada)
>
> kuldip singh wrote:
> > 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