while setting up inter vlan, I do not see option for encap

while settup up inter vlan with 1 switch (2950) which has two vlan and one router, I try to set the subinterface with separate ip address and encapsulation for dot1q but this router is not showing encap as an option..
What am I doing wrong? Also, what is the easiest way to search to see if certain command is supported under specific IOS version?

router2(config-subif)#encap?
% Unrecognized command
router2(config-subif)#?
Interface configuration commands:
arp Set arp type (arpa, probe, snap) or timeout
backup Modify backup parameters
bandwidth Set bandwidth informational parameter
bridge-group Transparent bridging interface parameters
carrier-delay Specify delay for interface transitions
cdp CDP interface subcommands
default Set a command to its defaults
delay Specify interface throughput delay
description Interface specific description
exit Exit from interface configuration mode
ip Interface Internet Protocol config commands
llc2 LLC2 Interface Subcommands
mtu Set the interface Maximum Transmission Unit (MTU)
netbios Use a defined NETBIOS access list or enable name-caching
no Negate a command or set its defaults
ntp Configure NTP
rate-limit Rate Limit
service-policy Configure QoS Service Policy
shutdown Shutdown the selected interface
snapshot Configure snapshot support on the interface
standby Interface HSRP configuration commands
timeout Define timeout values for this interface
traffic-shape Enable Traffic Shaping on an Interface or Sub-Interface

interface FastEthernet0/0
ip address 192.168.3.1 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet0/0.1
description subinterface for vlan 1

router2#sh ip int b
Interface IP-Address OK? Method Status Prol
FastEthernet0/0 192.168.3.1 YES manual up up

router2#sh ver
Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-I-M), Version 12.1(5)T9, RELEASE SOFTWARE (fc1)
TAC Support: http://www.cisco.com/tac
Copyright (c) 1986-2001 by cisco Systems, Inc.
Compiled Sat 23-Jun-01 20:13 by cmong
Image text-base: 0x80008088, data-base: 0x80972344

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Comments

wildfire

The 2950 only support 802.1Q and doesnt not support ISL, hence the encapsulation command is not available.

The router needs to be running 12.2 I think IP plus (IS) to run vlan routing, I can't remeber the exact IOS but if you have a CCO account you can use the feature navigator to find out which one.

agustinchernitsky

As Wildfire says, on 3550 switches (and greater?) you will have the switchport trunk encap cmd.

mikej412

convenientstore wrote:

interface FastEthernet0/0
ip address 192.168.3.1 255.255.255.0

Remove the IP Address from the physical interface

convenientstore

I think my version is good enough.. but I don't know why it's still not working. According to below article in cisco, earlier version than 12.1(3)T, you shouldn't specify the encapsulation(but my version is higher). I still tried without encapsulation option but I get below message with no ip ended up being assign to the subinterface itself.. What am I missing

http://cisco.com/en/US/tech/tk389/tk390/technologies_configuration_example09186a00800949fd.shtml

802.1Q Configuration on the Router for Cisco IOS Versions Earlier than 12.1(3)T

As described earlier in this document, while configuring 802.1Q trunking it is very important to match the native VLAN across the link. In the Cisco IOS software versions earlier than 12.1(3)T, you cannot define the native VLAN explicitly, as the encapsulation dot1Q 1 native command under the sub-interface is not available. In the earlier Cisco IOS versions, it is important to configure the native VLAN-Interface not as a sub-interface, which is in our example VLAN1. If configured wrong, the router would expect a tag dot1q frame on VLAN1 and the switch is not expecting a tag on VLAN1. As a result, no traffic will pass between VLAN1 on the switch and the router. In these situations always put the configuration for the native VLAN under the main interface and on the trunk create subinterface for all other VLANS.

router2#sh ver
Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-I-M), Version 12.1(5)T9, RELEASE SOFTWARE (fc1)
TAC Support: http://www.cisco.com/tac
Copyright (c) 1986-2001 by cisco Systems, Inc.

router2(config)#int fa 0/0.1
router2(config-subif)#ip address 192.168.3.1 255.255.255.0

Configuring IP routing on a LAN subinterface is only allowed if that
subinterface is already configured as part of an IEEE 802.10, IEEE 802.1Q, or I.

Interface IP-Address OK? Method Status Prol
FastEthernet0/0 unassigned YES manual up up
FastEthernet0/0.1 unassigned YES unset up up

convenientstore

someone please correct me.. I see below
which lead me to believe that I need software not only higher than number but also feature set has to reflect IS(IP PLUS).. am I correct on assuming this?

Router Models
Minimum Release Required for ISL Trunking
Minimum Release Required for IEEE 802.1Q Trunking
Minimum Required Feature Set (ISL/802.1Q)

Cisco 2620
11.3(3a)T
12.0(1)T
IP PLUS / IP PLUS

Cisco 2621
11.3(3a)T
12.0(1)T
IP PLUS / IP PLUS

Cisco 2620
12.1(3a)T
12.1(3a)T
IP PLUS / IP PLUS

Cisco 2650
12.1(3a)T
12.1(3a)T
IP PLUS / IP PLUS

Cisco 3620
11.3(1)T
12.0(1)T
IP PLUS / IP PLUS

Cisco 3640
11.3(1)T
12.0(1)T
IP PLUS / IP PLUS

Cisco 3661
12.0(5)T
12.0(5)T
IP PLUS / IP PLUS

Cisco 3662
12.0(5)T
12.0(5)T
IP PLUS / IP PLUS

Cisco 4500-M
11.3(1)T
12.0(1)T
IP PLUS / IP PLUS

Cisco 4700-M
11.3(1)T
12.0(1)T
IP PLUS / IP PLUS

wildfire

which 2600 model do you have? the 262X and 265X series support VLANs in nearly all IOS, but the 2610-12 need certain IOS version. I see you have a fast ethernet so Im assuming you have a 2620 or better. In which case the IOS is fine, did you do as Mike said and remove the IP from the main interface? try removing the ip and doing a shutdown, then config the sub-interface.

convenientstore

yes i tried that and it did not work.

cisco.com's doc says that in order to support this feature, I need to have IS.... and I have I.. Not sure if this is causing the issue. Trying to upgrade to IS but having tough time due to insufficient flash memory

keenon

convenientstore wrote:

yes i tried that and it did not work.

cisco.com's doc says that in order to support this feature, I need to have IS.... and I have I.. Not sure if this is causing the issue. Trying to upgrade to IS but having tough time due to insufficient flash memory

do u have a 2500 that u can scavenge the flash? i would suggest trying to get 12.2(29) for a 2600 alot of the 12.3 versions where messed up to say the least

convenientstore

upgrade took care of it.. very kool.. thank u guys