From: Jonathan V Hays (jhays@jtan.com)
Date: Sat Jul 26 2003 - 12:48:40 GMT-3
"I'm saying f0/11 is the SVI for Vlan 1026."
I respectfully disagree. The term SVI refers specifically only to the
Switched Virtual Interface, which is a unique entity created ONLY by
typing "interface vlan X" at the command line.
While it is true there is a relationship between an internal VLAN and a
routed port, this has absolutely nothing to do with Switched Virtual
Interfaces (SVI's).
I hope that clarifies.
Jonathan
-----Original Message-----
From: Deepesh Chouhan [mailto:deepesh@cisco.com]
Sent: Saturday, July 26, 2003 1:17 AM
To: Jonathan V Hays
Cc: ccielab@groupstudy.com
Subject: RE: Routed ports on the 3550
Hi
I guess we are saying the same thing, but in different ways.
I'm not saying vlan 1026 is SVI. I'm saying f0/11 is the SVI for Vlan
1026.
It is also its switchport. :)
Thanks
Deepesh
> -----Original Message-----
> From: Jonathan V Hays [mailto:jhays@jtan.com]
> Sent: Friday, July 25, 2003 6:29 PM
> To: 'Deepesh Chouhan'
> Cc: ccielab@groupstudy.com
> Subject: RE: Routed ports on the 3550
>
>
> Deepesh,
>
> Ah, I believe I understand what you are thinking.
>
> But although extended vlan 1026 was created by the software on your
> switch when you created routed port fa0/11, that does *not* mean that
> vlan 1026 is a switched virtual interface. A routed port forces the
> creation of a vlan for internal software usage, but it does not make
> that vlan into an SVI.
>
> For example, here I configure both an SVI (vlan 2 is 192.168.1.1) and
a
> routed port (fa0/1 is 172.16.1.1). Note that the SVI vlan has been
> configured as an access vlan on port fa0/2.
> ############
> Switch#sh run
> !
> [output omitted]
> !
> interface FastEthernet0/1
> no switchport
> ip address 172.16.1.1 255.255.255.0
> !
> interface FastEthernet0/2
> switchport access vlan 2
> switchport mode access
> no ip address
> !
> interface FastEthernet0/3
> no ip address
> !
> [output omitted]
> !
> interface Vlan2
> ip address 192.168.1.1 255.255.255.0
>
>
>
> On my switch, extended vlan 1027 was created by the switch IOS.
> ############
> Switch#sh vlan internal usage
>
> VLAN Usage
> ---- --------------------
> 1027 FastEthernet0/1
>
> Switch#
>
>
>
> But when I display a list of SVI's using the "show interfaces vlan"
> command, the switch indicates that vlan 1027 is not an SVI:
> ############
> Switch#show interfaces vlan 2
> Vlan2 is up, line protocol is up
> Hardware is EtherSVI, address is 000c.8581.6380 (bia 000c.8581.6380)
> Internet address is 192.168.1.1/24
> MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
> reliability 255/255, txload 1/255, rxload 1/255
> Encapsulation ARPA, loopback not set
> ARP type: ARPA, ARP Timeout 04:00:00
> Last input 00:06:13, output never, output hang never
> Last clearing of "show interface" counters never
> Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops:
2
> Queueing strategy: fifo
> Output queue :0/40 (size/max)
> 5 minute input rate 0 bits/sec, 0 packets/sec
> 5 minute ouxtput rate 0 bits/sec, 0 packets/sec
> 0 packets input, 0 bytes, 0 no buffer
> Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
> 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
> 0 packets output, 0 bytes, 0 underruns
> 0 output errors, 0 interface resets
> 0 output buffer failures, 0 output buffers swapped out
> Switch#show interfaces vlan 1027
> ^
> % Invalid input detected at '^' marker.
>
> Switch#
>
>
>
> Also, the "sh int status" output indicates that 1027 does not below to
> any useful vlan, as far as switching or routing is concerned.
> ############
> Switch#sh int status
>
> Port Name Status Vlan Duplex Speed
Type
> Fa0/1 notconnect routed auto auto
> 10/100BaseTX
> Fa0/2 notconnect 2 auto auto
> 10/100BaseTX
> [output omitted]
>
>
>
> The "sh ip int brief" command gives a list of IP addresses associated
> with SVIs and routed ports, and you can see that internal vlan 1027 is
> not included as an SVI.
> ############
> Switch#
> Switch#sh ip int brief
> Interface IP-Address OK? Method Status
> Protocol
> Vlan1 unassigned YES unset administratively
> down down
> Vlan2 192.168.1.1 YES manual up
> up
> FastEthernet0/1 172.16.1.1 YES manual down
> down
> FastEthernet0/2 unassigned YES unset down
> down
> Fa
>
>
> As a last test, I should be able to assign an SVI vlan to one or more
> layer 2 ports, as I did when I assigned SVI vlan 2 to interface fa0/2
> above. Let's see what happens if I try it on the unused port fa0/3.
> ############
> Switch(config)#int fa0/3
> Switch(config-if)#switchport mode access
> Switch(config-if)#switchport access vlan 1027
> % Access VLAN does not exist. Creating vlan 1027
> Switch(config-if)#
> 00:29:01: %PM-4-EXT_VLAN_INUSE: VLAN 1027 currently in use by
> FastEthernet0/1
> 00:29:01: %PM-2-VLAN_ADD: Failed to add VLAN 1027 - VTP error.
> Switch(config-if)#
>
>
> You have brought up a very interesting point. Thanks!
>
> Jonathan
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> Deepesh Chouhan
> Sent: Friday, July 25, 2003 8:50 PM
> To: Jonathan V Hays; ccielab@groupstudy.com
> Subject: RE: Routed ports on the 3550
>
>
> No
>
> Routed-port = SVI port of avaliable extended VLAN (1006-4096)
>
> switch-2#sh run inter f0/11
> Building configuration...
>
> Current configuration : 64 bytes
> !
> interface FastEthernet0/11
> no switchport
> no ip address
> end
>
> switch-2#sh vlan internal usage
>
> VLAN Usage
> ---- --------------------
> 1026 FastEthernet0/11
>
> switch-2#
>
> in this case
> routed-port f0/11 = SVI of 1026
> f0/11 = switchport of 1026
>
> So f0/11 is associated with VLAN 1026, but is also SVI of itself
>
> thanks
> deepesh
>
>
>
> > -----Original Message-----
> > From: Jonathan V Hays [mailto:jhays@jtan.com]
> > Sent: Friday, July 25, 2003 5:37 PM
> > To: 'Deepesh Chouhan'; ccielab@groupstudy.com
> > Subject: RE: Routed ports on the 3550
> >
> >
> > I think you mean that a routed-port does *not* have a VLAN number
> > associated with it, correct?
> >
> >
>
http://www.cisco.com/univercd/cc/td/doc/product/lan/c3550/12113ea1/3550s
> > cg/swint.htm#1035057
> >
> > quote:
> >
> > A routed port is a physical port that acts like a port on a router;
it
> > does not have to be connected to a router. A routed port is not
> > associated with a particular VLAN, as is an access port. A routed
port
> > behaves like a regular router interface, except that it does not
> support
> > VLAN subinterfaces. Routed ports can be configured with a Layer 3
> > routing protocol.
> >
> > end quote.
> >
> > Yes. I have seen little use for the routed port, other than playing
> > around with scenarios for the lab test. The SVI seems much more
useful
> > and flexible.
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