How about this ? This says 10-bit VLAN ID !
http://www.cisco.com/univercd/cc/td/doc/product/software/ios113ed/113ed_cr/s
witch_c/xcisl.htm
Frame Tagging in ISL
With ISL, an Ethernet frame is encapsulated with a header that transports
VLAN IDs between switches and routers. A 26-byte header that contains a
10-bit VLAN ID is prepended to the Ethernet frame.
--Gopinath
""Brant Stevens"" <[EMAIL PROTECTED]> wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
>
> Information on ISL header... taken from
> http://www.cisco.com/warp/public/741/4.html
>
> VLAN - Virtual LAN ID
> The VLAN field is the virtual LAN ID of the packet. It is a 15-bit value
> that is used to distinguish frames on different VLANs. This field is often
> referred to as the "color" of the packet.
>
> Information on 802.1Q packet... taken from
>
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121newft/121
> t/121t3/dtbridge.htm#xtocid114535
>
> The tag is stored in the following two octets and it contains 3 bits of
user
> priority, 1 bit of Canonical Format Identifier (CFI) and 12 bits of VLAN
ID
> (VID). The 3 bits of user priority are used by the standard 802.1p; and
the
> CFI is used for compatibility reasons between Ethernet type networks and
> Token Ring type networks. The VID is the identification of the VLAN, which
> is basically used by the standard 802.1Q and, being on 12 bits, it allows
> the identification of 4096 VLANs.
>
>
> Brant I. Stevens
> Internetwork Solutions Engineer
> Thrupoint, Inc.
> 545 Fifth Avenue, 14th Floor
> New York, NY. 10017
> 646-562-6540
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
> Gopinath Pulyankote
> Sent: Wednesday, February 28, 2001 1:49 PM
> To: [EMAIL PROTECTED]
> Subject: BCMSN: VLAN ID How many bits? 10 or 15 ??
>
>
> Hi all,
> The Cisco Press book BCMSN by Karen Webb says the VLAN ID is 15 bits,
> but I read somewhere else its 10 bits.
> Which is correct ??
> TIA
> --Gopinath
>
>
> _________________________________
> FAQ, list archives, and subscription info:
> http://www.groupstudy.com/list/cisco.html
> Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
>
> _________________________________
> FAQ, list archives, and subscription info:
http://www.groupstudy.com/list/cisco.html
> Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
>
_________________________________
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
