[sdnog] SVIs , Routed ports and L3 etherchannel overview

wadah khalid engwada7 at gmail.com
Sat Apr 1 13:22:16 SAST 2017

[ SVI - routed ports and Layer 3 etherchannals]

eng. Wadah A Osman .

Switched networks provide a Wild variety of features including logical
segmentation depending on the needed resources .

The need to provide a function that allow those different logical groups to
communicate is important , that's why I decided to show you an overview on
some features provided by Cisco to solve these problem .

First solution

¤ SVIs ¤

Switched virtual interface SVIs is a technology that used to provide inter
VLAN routing in the switched network and enables routing on the switch (
layer 3) .
The idea behind SVI is to make routing possible between different VLANs .

Enabling routing on the switch requires to change on the sdm prefer and
change it to lanbase-routing followed by reloading EXEC command . To
reserve some space from ASIC for ip routing table.

Then enable routing by #ip routing global command .
The next step is to add VLANs using interface VLAN ID and ip address
commands .

Second solution

¤ Routed ports ¤

Using the whole switch to perform SVIs is resource wasting thats why routed
ports show up .
A port is to be routed means that port can do layer 3 functions and move
from a layer port to layer3 port and will stop learning MAC address on that
port .

For enabling the routed port #no switccport subcommand will be used .
Then you can assign it with an ip address .
Creating VLANs with their ips on the switch have the routed port will allow
inter VLAN routing .

¤ Third solution ¤

Layer 3 etherchannels .

It combines the capabilities of  providing a redundancy on switched
networks and inter VLAN routing through routed ports .

The engineer first define the ports should participate in etherchannal
Issuing #no switchport on these ports with #no ip address subcommands .

Changing the port status to be routed . Then using #channel-group 1 mode on
subcommand .

The layer 3 information will be assigned to the virtual interface named
port channel
#interface portchannel 1
#no switchport
#ip address

Facing portchannel must be within the same subnet .
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sdnog.sd/pipermail/sdnog/attachments/20170401/4b77bda4/attachment.html>

More information about the sdnog mailing list