switches-vlans

[spivy66]

Can someone please explain what tagged and untagged ports are used for ..Correct me if i'm wrong but you can have more then one port on a vlan for perposes for vlan trunking? I also understand that if a untagged packet comes into a port on a vlan, then the packet gets a tagged according to the vlan id..What the point to tag packet.Would I just tag the ports that i'm using for trunking?I'm so confussed.Some examples would get helpfully too..Thanks!!!

 

[burtsbees]

VLAN tagging is done by the protocol, be it 802.1q or ISL (not used much anymore---802.1q is industry-wide). The router is the single port that passes vlan info to route between vlans, by way of configuring sub-interfaces on the one physical router inerface. Does this clear things up? You do not configure an interface for tagging, per say---you do configure it for the vlan protocol. I will come back in a bit with a sample.

Burt

 

[spivy66]

OK, I understand now that vlan taggg is done by a protocol. I'm not sure what you meant by " The router is the single port that passes vlan info to route between vlans, by way of configuring sub-interfaces on the one physical router inerface"...does this mean the port on the switch the router is pluged into passes vlan info?awating for examples,thanks again

 

[plshlpme]

when you have multiple vlans defined on your switch the only way to get hosts on different vlans to communicate is through a router..

so you will create one interface as a trunk to the router and then you will create a sub interface on the router for each vlan..

the router will then "route" packets between vlan for intervlan communication..

does that clear it up?

 

[spivy66]

Plshlpme,I have a trunk already setup..here's what I have

cisco 2600-->port 1 of netgear switch (trunked with pvid of 120 and in part of vlan 2)
netgear port 2,3 in same vlan2 with pvid of 120 trunk-->another netgear switch in different closet
port 2,3 with same values above. IS this right?? If so do I need to setup some thing on the cisco 2600? and I'm still not sure what tagginf and untagging does ?..thanks for your help

 

[Minue]

Hello
The techs on this forum are all cisco freaks.Most of us have studied intergrating all cisco equipment.Even Cisco advices against mix equipment.But being that 802.1q is not proprietary protocol maybe it possible to make the 2600 trunk the netgear traffic.
Please state which model of the 2600 series you are using and what's your objective.
Regards

 

[spivy66]

ok here is what I want to know ..two things..

1. what is the point of tagging ports..is it just used for trunking?

2.is there a command i need to set on my 2600 cisco router to trunk to another switch wheather it be a cisco or netgear?Neargear supports the 802.1q protocol.

Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-I-M), Version 12.2(5d), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Sat 02-Feb-02 03:36 by kellythw
Image text-base: 0x80008088, data-base: 0x80989870

ROM: System Bootstrap, Version 12.2(10r)1, RELEASE SOFTWARE (fc1)

uptime is 4 weeks, 2 days, 3 hours, 11 minutes
System returned to ROM by power-on
System image file is "flash:c2600-i-mz.122-5d.bin"

cisco 2651 (MPC860P) processor (revision 0x00) with 27648K/5120K bytes of memor
.
Processor board ID JAD06350CI4 (2539810080)
M860P processor: part number 5, mask 2
Bridging software.
X.25 software, Version 3.0.0.
2 FastEthernet/IEEE 802.3 interface(s)
32K bytes of non-volatile configuration memory.
8192K bytes of processor board System flash (Read/Write)

Configuration register is 0x2102

 

[Minue]

Hello
Below is a typical configuration to allow inter-vlan routing.As you can see every VLAN has it's own network.On the netgear are you using different subnets for the VLANs that you have created?
Vlan tagging is done on the packets traversing the switch.Every packet have a field saying which vlan it belongs to.You don't tag ports!You trunk ports on routers and you make VLANS on switches.Vlans are created for security reasons and sometimes performance.
Hope this helps


Router_A(config)#interface fastethernet 0/0
Router_A(config-if)#no shutdown
Router_A(config-if)#interface fastethernet 0/0.1
Router_A(config-subif)#encapsulation dot1q 1
Router_A(config-subif)#ip address 192.168.1.1 255.255.255.0
Router_A(config-if)#interface fastethernet 0/0.2
Router_A(config-subif)#encapsulation dot1q 10
Router_A(config-subif)#ip address 192.168.5.1 255.255.255.0
Router_A(config-if)#interface fastethernet 0/0.3
Router_A(config-subif)#encapsulation dot1q 20

 

[spivy66]

Thank you,but my cisco 2600 does not allow me to use encapsulation command,I guess I have an older iso?

Yes i did setup the other vlan i have two , default and vlan 2

the default is 192.168.1.0/24 and vlan2 is 192.168.2.0/24

the interface on the router f0/1 is assagined 192.168.2.2

So it pretty stright forward..I have that interface plugged into the netgear switch in port 1 which is assaigned to vlan2 with a pvid of 120.So if i cant config the cisco to port trunking that i'm unable to have a trunk?

 

[burtsbees]

Yes, I would say the IOS is more than likely IP-base code, which is basic code. Post a sh ver.

Burt

 

[spivy66]

Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-I-M), Version 12.2(5d), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Sat 02-Feb-02 03:36 by kellythw
Image text-base: 0x80008088, data-base: 0x80989870

ROM: System Bootstrap, Version 12.2(10r)1, RELEASE SOFTWARE (fc1)

uptime is 4 weeks, 2 days, 3 hours, 11 minutes
System returned to ROM by power-on
System image file is "flash:c2600-i-mz.122-5d.bin"

cisco 2651 (MPC860P) processor (revision 0x00) with 27648K/5120K bytes of memor
.
Processor board ID JAD06350CI4 (2539810080)
M860P processor: part number 5, mask 2
Bridging software.
X.25 software, Version 3.0.0.
2 FastEthernet/IEEE 802.3 interface(s)
32K bytes of non-volatile configuration memory.
8192K bytes of processor board System flash (Read/Write)

Configuration register is 0x2102

 

[Minue]

Hello
I think you aren't building the sub-interfaces,you get the "encapsulation dot1q" command only in the sub-interfaces mode.Read former post again to see how it done.
Also note that you can't put an ip address on the physical interface.
To comfirm that you can support dot1q please do these commands:
Router(config)#interface fastethernet 0/0
Router(config-if)#interface fastethernet 0/0.1
Router(config-subif)#encapsulation ?

You should see the below output.In any case post what you see.
dot1Q IEEE 802.1Q Virtual LAN

 

[spivy66]

I know, look...

17.2mask(config-subif)#encapsulation ?
% Unrecognized command

here's the ? in the root of subif

17.2mask(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
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 HSRP interface configuration commands
timeout Define timeout values for this interface
traffic-shape Enable Traffic Shaping on an Interface or Sub-Interface

17.2mask(config-subif)#

 

[Minue]

Hello
Sorry for doubting you.But I just did my homework ,you will need an IP Plus.This is the minimum requirement "IOS 12.1(5)T, IP PLUS"
Being that you have a small flash,you may have problems upgrading,because the ip plus IOS is quite large on the 2600 series.
Let me know how it goes.
Regards

 

[Feliz]

Hi,

Try to use the "encapsulation" command on the router fastethernet main interface, and not on the sub-interface.

ex:
Router(config)#interface fastethernet 0/0
Router_A(config-if)#encapsulation dot1q

Regards,

Feliz

 

[burtsbees]

Sorry, Feliz, but you need it on the subinterface, with the IP Plus code.

Burt

 

[spivy66]

What is the IP Plus?..can i get this for free or is cisco going to kick me in the dix

 

[Minue]

Hello
Cisco offers nothing free,if you don't have a CCO account.Anyway the IOS you need will look like this "c2600-is-mz.121-24" with the "s" in the file name.The below website tells how to get a cisco IOS.

http://www.cisco.com/warp/public/732/licensing.shtml

Good luck

 

[burtsbees]

Or...

http://www.ebay.com

Burt

 

[plshlpme]

1. what is the point of tagging ports..is it just used for trunking?

im not sure what your after here..
when you have multiple vlans defined on your switch you need to have tagging applied so that the switches and routers know what vlan the traffic belongs to.

you create vlans in order to isolate different lans at the logical level.

when you hit the router where you normally have a subinterface defined for each vlan it will then go to the proper subinterface based on that tag.

do you know what im trying to say?

if you have port 1 in vlan 1
and port 2 in vlan 2

and plugged a pc into port 1 and another pc into port 2
they will not be able to talk to each other

if on port 3 you enable trunking and go to a router and create a subinterface for vlan1 and another subinterface for vlan2 it will the "route" traffic between the vlans.

hope the helps some...