21

Is it correct in assuming that ASICs for router or switch interfaces will outperform the use of an x86 CPU for all packet processing which will greatly suffer from CPU interrupts? It's hard to say specifically whether interrupts are a limitation, since we aren't naming specific CPU, operating system or router models in this part of your question. Overall, ...


15

The Cisco 2960-X is an IOS platform. According the to the datasheet it ships with LAN Lite, LAN Base, or IP Lite(all IOS variants) depending on the hardware you select. You may want to consult the documents linked below to determine what feature(s) you require, as the lite models cannot be upgraded to the comparable base IOS version. 2960-X Data Sheet 2960 ...


12

I think that you have another switch or hub connected to port 24 of your 2960, and there are 4 hosts connected to that switch/hub.


12

You really, really do not want to disable STP where you connect switches to other switches. That is the entire purpose of STP. If you disable STP, and there is a problem, it will really be too late because your entire network could crash when you notice it, and recovering from a broadcast storm is no fun at all. By the way, portfast doesn't actually disable ...


11

3750 does have some internally priority on what it prefers to punt when congested, but it's not configurable. So you should rely on common best practices, that is on all your network edges you should have iACL (infrastructure ACL). In iACL you'd allow UDP highports, ICMP to infrastructure network addresses and drop rest. This way ping and traceroute work, ...


11

You can use short range SFP optics for this. The Cisco part number is GLC-SX-MM, and the cost is about $75-$100 each (you'll need two). The person installing your fiber should use 50uM multimode fiber (62.5uM is also useable, but you're getting close to the maximum range) with LC type connectors.


11

tl;dr The switch management cannot send anything to a different layer-3 network without a default gateway. Telnet is a bidirectional protocol, and the switch, without the default gateway, would be unable to respond to the host which is attempting to establish the Telnet session. Long explanation: The default gateway on a switch has the same function as ...


9

Depending on the actual "Metro Ethernet" service that your carrier is providing, you have several possible solutions. I'll address what I see as the most likely scenario, and some of the solutions in that scenario. Your carrier is probably using Q-in-Q tagging, and your local VLANs are irrelevant. (See the Wikipedia page on 802.1ad for info on Q-in-Q, or ...


9

Does it mean that if I save this line to configuration license boot level ipbase | entservices, I will have working perpetual Enterprise License but with some warnings in syslog? You will get the entservices features for free "today", as long as you're willing to ignore the syslog messages. At some IOS in the future, they might start enforcing licensing ...


9

You can specify an interface to receive an address from DHCP like this. configure terminal interface (int-name-num) ip address dhcp This guide gives way more detail into DHCP features - Cisco DHCP Client Configuration You should note that there are additional commands to the ones I listed, but they are optional.


9

If you didn't save the configuration, you could just restart the switch, but you will need physical access to the switch. You may be able to get someone at the site to restart the switch for you. Simply unpluuging it, waiting a few minutes, then plugging it back in should work. Also, Cisco maintains a Password Recovery Procedures web page with links to the ...


8

This configuration works on our other switches, but it doesn't work on this 4500. You're using the on-board Sup7 FastEthernet port, so this is your problem: aaa authentication login default group tacacs+ local ^^^^^^^^^^^^^ The Sup7 OOB port is in a VRF; therefore, you have to configure Tacacs+ in a VRF aaa new-model ! no ...


8

I've kept digging around the internet....and I think I've answered my own question. Now I need to go back to the application/device owners/developers and see what we can do or further lock these devices down to their own VLAN. Please leave comments or answers with any further advice. RFC 4541 2.1.2: 1) Packets with a destination IP address outside 224.0.0....


8

my own solution comes out in the form of iso.3.6.1.2.1.17.4.3.1.2.0.20.42.49.139.235 25 ... do the other numbers represent a MAC address and if so, why are they different from the give solution? First, I apologize for not including this dependency... The MIB tables you're polling are indexed by a value. In this case, you're polling ...


8

As you found, the port is plugged into a phone; so until the phone cycles the port will stay up. Regarding the portfast command; when a switchport comes up, spanning-tree moves through a series of states to bring the port up. Legacy spanning-tree took 15 seconds in the Listening state and another 15 seconds learning. During that time, the port cannot ...


8

Spanning tree only runs between switches, never to standard end hosts. Bear in mind that, under normal circumstances, a port supporting spanning tree will (when it first comes up) run through a sequence of first listening for BPDU's, then learning source addresses and then finally forwarding frames. This can take ~30 seconds, during which the connected ...


8

You can disregard the dedicated management interface and simply assign an IP address to the VLAN 500 interface on the switch and use this IP for management purpose, with appropriate access lists. FE0 is useful for out of band management. Nothing prevent you to perform in-band management without it.


8

I was wondering if there was a way to switch out the VLAN ID from VLAN1 to VLAN10 without impacting the connectivity of the end users? No. First, you must remove the addressing from VLAN 1 before you could put that same addressing on VLAN 10 (interfaces cannot have the same or overlapping addressing). Next, if that address is your gateway, then you will ...


7

some support for @ytti 's answer above, hope it helps: orange#sh ver Cisco IOS Software, IOS-XE Software, Catalyst 4500 L3 Switch Software (cat4500e-UNIVERSALK9-M), Version 03.04.00.SG RELEASE SOFTWARE (fc3) … orange#sh mod Chassis Type : WS-C4507R+E Mod Ports Card Type Model Serial No. ---+-----+-------------------...


7

What you are trying to achieve is done with VLANs. A VLAN is basically a logical L2 domain so two hosts on the same VLAN will be able to communicate without a router. Trunking basically means 'allow more than one VLAN on the same port'. You can do that to allow a host to be able to connect to different VLANs using the same port or for interswitch ...


7

In a word: YES. Unless you want to do something like force a 10G SFP+ to link at 1G, you don't have to do anything but plug it in.


7

Open a TAC case as these may be affected by this Field Notice. This revolves around a known memory issue by parts from a particular supplier that have a high failure rate. These parts have been included in many different platforms including many models of the 2960 line. You can find the main page discussing this issue and providing a number of field ...


7

Your subnet mask is 255.255.0.0 (also written as /16). That means the first 16 bits of the IP address define the network, and the last 16 bits are the host address. With that mask, there are 65534 possible hosts. In your case, the first 16 bits are the same. That means both IPs are in the same subnet. That's why your switch is complaining. Remember ...


7

I have a setup with dual redundant Cisco catalyst 4506-E using the WS-X45-SUP8L-E supervisor engine and two 48-port switches below it. My task is to access and modify the switch configuration. Access shall be accomplished locally only, through console port using serial cable and user/pass combo. The notion that "thou shalt not use ssh / telnet /...


7

The order of operations is important because setting the time first will result in the time being incorrect after issuing the zone commands, so what you need to do is: First, you set the regular time zone at the configure terminal prompt using: clock set timezone <standard zone> <offset> For example: clock set timezone EST -5 Then, you set the ...


7

In addition to @Zac67 answer, in the Catalyst product line, layer 3 capabilities are often unlocked by licenses. So a given switch can be layer 3 capable but, depending on the installed license, may have none, a few, or a complete set of, layer 3 features. The switch is shipped by default with the LAN BASE license (formally LAN lite), but can be either ...


6

There is another caveat: Depending on platform, the switch will punt all link-local multicast to the CPU. This includes for example OSPF traffic. I noticed this on Ciscos Catalyst 4500 which will send all 224.0.0.x traffic to the CPU. When the CPU is busy it will drop the packets, including your OSPF packets. Have fun debugging why your OSPF session(s) drop....


6

Please ping the DHCP machine before polling. After the ping, tables will be populated. If you can't ping the DHCP laptop, then you know why you can't see it in the ARP table.


6

You probably want to be polling the CAM/MAC tables, that would have the MAC address of any devices send any traffic through the switch. ARP is L3 CAM/ARP is L2


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