LAN Ethernet vs WAN Ethernet

Answered Question
Feb 15th, 2012

Hi,

I own a Cisco 892W router. The router has 2 WAN ports and 8 switch ports.

Now I know -

-WAN ports can create sub interfaces, assigne IPs, cannot be assigned to a VLAN - sounds very much like a routing port. (sh interface gives - Hardware is PQII_PRO_UEC)

-Switch ports are for VLAN assignment, trunking, IP assigment etc,. (sh interface gives Hardware is Fast Ethernet)

I know they are different but at the same time confuced what the difference are? I also know on some 3xxx series switchs you could say "no switchport" and translate a switch port to a layer 3 port. But on 892W you can't do this? Struggeling to understand the difference.

Appreciate if someone could help me understand this

Thanks in advance,

I have this problem too.
0 votes
Correct Answer by naiduccnp about 3 years 2 months ago

Hi,

The two WAN ports what you are saying are L3 ports which means you can assign IP and configure sub-interfaces for different networks nothing but VLAN's
And you can terminate the WAN link (ethernet handoff from provider) can connect to these ports and do routing.

The remaining 8 switch ports, it is actually a switch module available on that router, these are L2 ports you can not assign any Ip address to it neither do subinterfaces.

The two WAN ports are designed only for WAN network purpose thus do L3 job also.


Please rate all the helpfull posts.
Regards,
Naidu.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4.5 (3 ratings)
Correct Answer
naiduccnp Wed, 02/15/2012 - 02:44

Hi,

The two WAN ports what you are saying are L3 ports which means you can assign IP and configure sub-interfaces for different networks nothing but VLAN's
And you can terminate the WAN link (ethernet handoff from provider) can connect to these ports and do routing.

The remaining 8 switch ports, it is actually a switch module available on that router, these are L2 ports you can not assign any Ip address to it neither do subinterfaces.

The two WAN ports are designed only for WAN network purpose thus do L3 job also.


Please rate all the helpfull posts.
Regards,
Naidu.

Richard Burts Wed, 02/15/2012 - 05:20

I find this terminology awkward and potentially confusing to call them WAN ports. As Naidu points out what you have got is a router with two router Ethernet interfaces and a switch built into the router so you have 8 switch ports.

The router Ethernet interfaces could be used for WAN connections but could also be used for LAN connections (connecting to an external switch etc). But Cisco has chosen to identify them as WAN ports. The switch ports are typical switch ports and you can do normal switch type configuration on them (vlan assignments, trunking, etc).

HTH

Rick

oshadharanaweera Thu, 02/16/2012 - 02:07

Thanks for both replies - helped me a lot understanding the problem. Cheers !!

The confusion I had was that on those switch ports the "IP address" command was an option - this lead me thinking that these switch ports could be configured layer 3. However, when you actually try to configure the switch port with an IP it fails.

- How does WAN ports of 892W differs from a layer 3 switch like 3750? I can't seems to use "no switchport" command on 892W's WAN interfaces?

- Also on 892W, how does the embedded WLAN-Gigabitethernt 0 differs from the normal switch ports? On the router end it appears as if its layer 2 port. However, on the AP end its appears as if it is a layer 3 port.

Thanks in advance.

naiduccnp Fri, 02/17/2012 - 02:46

Hi,


- How does WAN ports of 892W differs from a layer 3 switch like 3750? I can't seems to use "no switchport" command on 892W's WAN interfaces?
Those are routed ports, you no need to do "no switchport"


- Also on 892W, how does the embedded WLAN-Gigabitethernt 0 differs from the normal switch ports? On the router end it appears as if its layer 2 port. However, on the AP end its appears as if it is a layer 3 port.
Not much idea about the WLAN port
Have not experienced it still.
I think the Gigabitethernt 0 is a L2 port to connect your AP.

You can also see the below thred for more information regarding AP connectivity and all.
https://supportforums.cisco.com/thread/2117214


Hope the above clear and understand you.

Please rate all the helpfull posts.
Regards,
Naidu.

Actions

Login or Register to take actions

This Discussion

Posted February 15, 2012 at 2:28 AM
Stats:
Replies:4 Overall Rating:4.5
Views:3891 Votes:0
Shares:0
Tags: No tags.
 

Discussions Leaderboard

Rank Username Points
1
Jon Marshall
16,857
2
Reza Sharifi
9,379
3
Giuseppe Larosa
8,202
4
Leo Laohoo
7,684
5
Peter Paluch
7,654
Rank Username Points
Jon Marshall
469
Joseph W. Doherty
141
Reza Sharifi
105
Leo Laohoo
98
Peter Paluch
71