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Difference between console port and dedicated management port

Clay Plaga
Level 3
Level 3

Can someone explain what the difference is between the console port and the dedicated management port(fa0) , on a Cisco 2960s switch.

Thank You.

25 Replies 25

Leo

How does it know where to send packets for remote subnets ie. if the destination IP is on the same subnet it sends it direct but if it is on a remote subnet it needs to send packets to a L3 device for routing.

So it needs some way of knowing which to do.

Or can you not manage it remotely ?.

Jon

Hi Jon, 

 

The Management port, FastEthernet0, doesn't "understand" default gateway.  There is not a lot of stuff you can configure with this port.  One of them is an IP address.   Think of it as a "PC" and somehow attached to the motherboard using a "psuedo" connection.  

 

Layer 3 stuff you're asking.  Right, you're suppose to connect the Management port to a switch.  And the switch goes up to another router.  The router's IP address is an OoBM IP address.  

So you can't manage these remotely then and by remotely I mean from a different IP subnet than the IP subnet used for the management port ?

Because the switch has to know whether the mac address it should use is the mac address of a client ie. the PC is on the same IP subnet or whether the mac should be the L3 devices mac address ?

Never used them so just trying to understand what you can and cant do this with this port.

Jon

So you can't manage these remotely then and by remotely I mean from a different IP subnet than the IP subnet used for the management port ?

Let's presume that your production network is 10.0.0.0/8.  Let's presume that you've got an OoBM network running on 192.168.0.0/16 and this network is NOT routable into the 10.0.0.0/8.  The switch will, of course, understand 10.0.0.0/8 network  

 

The router at the core will only talk 192.168.0.0/16.  It will not understand 10.0.0.0/8.  The OoBM doesn't really have a link into the 10.0.0.0/8 network.  This is what the main intention of the Management port.  In some cases I've seen, the only way "in" to the OoBM network from the 10.0.0.0/8 network is via a console server.  

Never used them so just trying to understand what you can and cant do this with this port.

Yeah.  Me too.  And knowing Cisco (lately), documentation (about the configuration guide about the Management port) really s*cks.  

 

I know Management port/interface don't use default-gateway because I use the port for ZeroTouch SmartInstall.  All I do is assign (via DHCP) an IP address to the Management port and the VStack Director talks to the client/slave switches just fine.  And just because of this, my configuration templates for ZeroTouch SmartInstall always have the Management port disabled and interface has no configuration.  

If i disable line vty with this command

line vty 0 15

no transport input

 

can i still telnet to my int mgmt 0 that is there on the switch ?

I think I need to add something to this point. 

In todays converged network, most of the companies use Console Servers such as OpenGear, MOXA and etc. So the idea that Console port is used to have physical access and management is used for remote management is not so accurate. 

There has to be a concrete difference. My question is If i have Console Server (like OpenGear) and I can access my switch from any location in the world, do I need to configure my management port also??? 

Would be thankful for an answer. 

Do you "need" to configure your management port also? I would say that as long as you have one that works then you do not "need" an alternative. A somewhat different question might be whether you "want" to configure an alternative. For most of us a single management connection capability is enough and we do not want the extra work and complexity of configuring an alternative for management. Some people get very worried abut failure scenarios and ways to work around potential failures of the primary management path and would want to configure the management port. 

HTH

Rick

Could you please write me the differences between them, not on abstract level but with bit detail and which one to use and where? thank you 

I am not clear what you do not understand in the previous responses, but let me try to explain the differences this way:

- console is intended for direct connection of some device (PC etc) to the router/switch. This connection does not use Ethernet and does not use IP networking. So it is not effective with devices that are physically remote. It is very effective in doing configuration, observing log records in real time, checking device status in real time. 

- management port does use Ethernet and does use IP networking. So it can be effective in communicating with devices that physically are not local. It could be used for configuration, but is most effective for sending/receiving SNMP, syslog, tftp/ftp. So the management port is less effective in real time/current observation and more effective in providing a historical view of what has happened to the device.

HTH

Rick


@ahmedaburaihan wrote:

I think I need to add something to this point. 

In todays converged network, most of the companies use Console Servers such as OpenGear, MOXA and etc. So the idea that Console port is used to have physical access and management is used for remote management is not so accurate. 

There has to be a concrete difference. My question is If i have Console Server (like OpenGear) and I can access my switch from any location in the world, do I need to configure my management port also??? 

Would be thankful for an answer. 


Hmm, cannot comment on most companies using Console Servers for network devices, now a days.  Back when I retired, which has been some years now, it wasn't common for network devices, although terminal servers have been, for years, available to also remote access a Cisco network device's console port, either in-band or out-of-band.  (Heck, at sites with two WAN routers, could use aux port on each router to reverse telnet to peer router's console port.)

In fact, my experience most network devices used an in-network management IP for 99.9% device management and only resorted to even using the console port when there was some issue where we wanted to see the console output.  A dedicated physical management port, if network device had one, was almost never used.

But, assuming a console port was speed and/or feature restricted, I might very much want a management port to provide network "speed" access, in a more secure path, than using just a management IP available on an "ordinary" port.

So perhaps, yes, there's isn't much "need" for a dedicated management port, "back then" or today, but for some use cases, it might be a desirable, or in the eyes of the users, a "needed" feature.

In my experience, difference companies often have very different viewpoints on what they believe they need, especially before vs. after some "event".  Much "need" goes hand-in-hand, with cost, also again before vs. after some "event".

Joseph W. Doherty
Hall of Fame
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A console port is special for two reasons.  First, it's "known" to the system as its console port which means the system will send status information to it, and often treat it special when accepting input.  Second, the console port is generally wired as a serial port.  (It also normally doesn't have an IP address.)

The console port was intended for where the system operator controls the system from, usually nearby (physically).  (Console ports are/were used for any computer based system.)

Management ports are generally for remote management using an Ethernet port.  On older switches/routers, a device might be configured to use an ordinary Ethernet port for this purpose.  On newer switches/routers, a Ethernet port is provided for this purpose. For these, the device may actually use different hardware for port and might treat it internally differently.  For example, often the Ethernet management port is only FE, it may not have ASIC support for high speed switching, and it might be in it's own predefined VRF.  Generally, a management port will have an IP address, but different from  IP address spaces used by other hosts.

Out-of-the-box, a console port will allow you to configure the device, but a management port will often require some additional configuration.

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