Questions tagged [switch]

For questions about network switches, the term commonly refers to a multi-port network bridge that processes and routes data at the data link layer (layer 2) of the OSI model.

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6
votes
1answer
2k views

Cisco CatOS - show port usage output

I'm in the process of replacing some switch blades and i'm looking through the show port usage command on the older catos switches. I'm struggling to understand the output for the show port usage ...
4
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2answers
1k views

Stacking Different Model Dell Switches

I have 2 brand new Dell 5448 1 Gbps switches and an older 3448P. The newer switches stack with each other via an HDMI cable and have the ports for fiber optic, but the older 3448P switch has no HDMI ...
3
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1answer
2k views

Routing of 2 Gateways via a Layer 2 Switch

Please refer to the network diagram below, it is a very simplified version of an actual network installation. The Router has 3 Vlans, OSPF has been configured and all the 3 vlans have been added to ...
5
votes
1answer
35k views

Difference between gateway, router, switches and bridge

I am going through a course of networking and want to know the difference between the mentioned devices. I have heard that the switches: Establish a temporary connection between the devices connected ...
1
vote
1answer
521 views

ECMP between next-hops with different route prefix length

I have a basic question about ECMP, say I have a /20 route and also a /16 route to a host, and both are reachable, can ECMP load-balance between different prefix length or is it like, hardware first ...
7
votes
2answers
11k views

Aggregate bandwidth of a gigabit switch

This one might be the dumber question ever asked in this place, but here it is: If I have 20 machines, all equipped with gigabit ethernet NICs, all connected to a gigabit switch, is the maximum ...
6
votes
3answers
2k views

Circuit and Packet Switching

I'm struggling to understand 1 or 2 things about packet and circuit switching. In circuit switching, resources are not shared and a it's guaranteed full capacity to the call right? They are "reserved"...
6
votes
4answers
8k views

Switch Lookup Table

I was just reading a book called HeadFirst Networking and I'm a bit confused about something. I am attaching an image from the book. The page says that the direction of the frames as maintained in the ...
4
votes
1answer
649 views

Cat6K parity failure and long SSO failover

From a Cat6K, RP crashinfo indicates parity error. Guidance seems to be to not do anything unless this happens more than once in 12-month period. At what point do you push Cisco for hardware or RAM ...
5
votes
1answer
4k views

What is the correct way to determine SFP+ Direct Attach cable compatibility between switches and NICs?

I'm contemplating a 10 Gigabit link between an Intel x520 NIC and a Cisco SG500X switch. These two would be within 5m of one another, so using one of the Cisco SFP+ passive Direct Attach cables like ...
0
votes
1answer
167 views

Igmp snooping based multicast forwarding

In Igmp snooping switch receives an Igmp leave report? Is it possible to change the timeout value in Igmp snooping switch?
5
votes
1answer
922 views

IGMP snooping in iptv

Host1 wants to join Multicast group as IGMPv3 include (G,S). The same group and source Host2 send as Exclude(G,S) report. what process done in switch?
8
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2answers
9k views

Cisco ASA Routing Issue

I am working on a lab right now and am having some issues with ASA routing. Here is the current network topology: Currently if I login to the console on the ASA or Router I can get outside to the ...
7
votes
5answers
20k views

Copy running config in one line

I want to make a script to copy the running config of a switch 4506 in one line. So far, I see two option : copy run tftp: sw#copy run tftp://10.0.0.1/cfg.cfg Address or name of remote host [10....
4
votes
2answers
507 views

IGMP snooping (Bridge operation)

What is Meant by RFC 4541 when it says... 4) All non-IPv4 multicast packets should continue to be flooded out to all remaining ports in the forwarding state as per normal IEEE bridging operations.
2
votes
3answers
6k views

Can I route packets to different VLANs based on destination IP?

I have a network that consists of 3 VLANs: 1 -> Desktops and Laptops 50 -> IP Cameras 200 -> Servers Just to make this simple, treat all devices in a VLAN the same: 1 is a member of 200, as ...
8
votes
1answer
2k views

Something is filling my force10 ARP table

I have 2 force10 s25 switches that are used for a dark fiber link between two school buildings. One of my switches is filling its ARP table to the brim and then failing. This can happen as often as ...
13
votes
3answers
15k views

Tracking down an invalid source mac address

I have inherited support of a remote site which contains a Cisco 4500 and is connected to ~2 dozen cisco access switches - primarily 2960s with a couple of 3750s and 3560s. Not all access switches ...
3
votes
1answer
3k views

Simple circuit-switched network

I'm having a problem understanding this question regarding circuit-switched networks. I get the main concept that the connections are reserved for each link, but these two questions are confusing me. ...
40
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4answers
35k views

Bits per second vs. Packets per second

Lately I have been checking datasheets of several switch models from diferent vendors. For a given switch, vendors publish a couple of figures that I think are a measure of the capacity/performance of ...
6
votes
3answers
2k views

Typical throughput on switched network

I recently got around to measuring effective throughputs on a pretty big, switched network. I measured the throughputs by having two laptops, both running Iperf; one being the server, the other a ...
4
votes
1answer
426 views

Question about design of a small/medium office network

We're a smallish business about to move to a larger space, so I have a question about the way we've wired our network. Our current scheme is to use smaller switches (8 ports) at each "cluster" of ...
4
votes
1answer
253 views

Cisco switch generates two pairs of keys

The problem is: I generate a key pair on a switch and when i use: show crypto key mypubkey rsa it shows two keys. A geral-purpose key and an encryption key. The general-purpose key is the key i ...
2
votes
1answer
2k views

Browser access to HP ProCurve 1400-24G

My workplace has a HP 1400-24G J9078A switch. I want to connect to it via browser. I tried the manual and other options but could not find any reference.
9
votes
1answer
1k views

Label Distribution Protocol(LDP) in MPLS

I have been going through the MPLS technology recently.I have this doubt in my mind after reading some of the features of the MPLS. A---B---c | | D----E Lets say routers A,E are LER and B,...
33
votes
1answer
64k views

Using SNMP to retrieve the ARP and mac-address tables from a switch

I would like to get ARP tables from a switch to a syslog-ng server that has been set up on Ubuntu Server 12.04 LTS. I have read about SNMP and I know the server will act as a manager and the switch as ...
19
votes
2answers
23k views

Ethernet autonegotiation differences between (10M | 100M | 1G) Ethernet

I am studying for CCNA and on Wendell Odom's book is said that(regarding autonegotiation): When autonegotiation fails on one node, to choose (half/full-duplex) we must use the rule: If you have a 10/...
10
votes
1answer
3k views

Long login delay when cisco device is booted

Whenever we boot or reboot a Cisco router or switch we have to wait a number of minutes before we can get a username prompt for login. We get a few fail messages Press RETURN to get started. % ...
6
votes
2answers
6k views

SFP / Fiber Link Issue - Can't connect a Fiber CPE

I've a CPE connected to a 4506 switch. The interface is Up but I don't see traffic CPE MAC address on MAC sddes-table I've already replaced the cable, SFP and port. Now I've the minimal config (...
9
votes
1answer
5k views

switchport block multicast vs storm-control multicast

I'm not sure what is the difference in behaviour between switchport block multicast and storm-control multicast and I don't think cisco elaborates the difference very well in their documentation, ...
6
votes
1answer
5k views

Chassis temperature and Fan status on Cisco 3548 switch

I need to remotely check the status of the fans and temperature of a switch that I currently do not have physical access to. I have done so in the past on a 2950 with the command: Show environment ...
8
votes
1answer
2k views

Private-vlan configuration - connectivity issue

I've an issue leading with Private Vlans. I've fiber modem and they can't reach the DHCP/TFTP to be provision. I suspect from the configuration of Private VLANs. Can you review them ? My doubts are ...
5
votes
3answers
5k views

REP (Resilient Ethernet Protocol - Cisco Proprietary) configuration

I've the challenge to configure REP on a ring with 2 4500-X and 2 4506 as you can see on topologie picture. I was able to configure a basic REP ring but don't know how to define the block port as on ...
15
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2answers
1k views

In what mode does the 2960-S IOS prompt ends with a colon “:”

QUESTION For a Cisco 2960-S switch, when connecting on the console port, normally the prompt is: SwitchName> then you issue an enable command and end-up with a prompt like: SwitchName# However,...
5
votes
1answer
793 views

Fiber Port Issue

I'm trying to troubleshoot a situation between a foundry sx and a brocade icx. I setup tagged ports and vlans between them both. Now when I connect the 2 switches with an ethernet cable, ospf comes ...
7
votes
4answers
477 views

How can I avoid having to change the vlan back and forth when imaging pc's

We are using PXE boot to image computers from Win XP to Windows 7. The powers that be have created an imaging vlan dedicated specifically for this purpose, presumably for load balancing? The problem ...
4
votes
1answer
1k views

HP Procurve 5406 Traffic Control Via VLANs and STP

I know that Cisco gear can do this, but can a Procurve be made to do it as well? I have a scenario of around 16 access switches, one switch per building, connected to two aggregation/core switches ...
17
votes
7answers
51k views

Cisco command to show which interfaces an ACL is applied to

For Cisco routers and switches, is there a show command, or something similar, that will display what physical and logical interfaces an ACL is implemented on and what direction it is applied in? I ...
2
votes
4answers
22k views

Ethernet device works on certain ports on Ethernet switch but not on others

I have a small and inexpensive ethernet switch which is giving me some headache. For some reason some devices only work when I plug them into specific ports. The ports are not broken, as other devices ...
9
votes
2answers
1k views

Switch-Assisted Load Balancing w/ Fault Tolerance

While studying for Cisco and Microsoft certifications I read a lot about NIC Teaming, Etherchannels and similar stuff. I know you can do static teaming in MS Windows Server or creating a port-...
19
votes
1answer
3k views

Finding transparent firewall packet loss

We use the Cisco ASA 5585 in a layer2 transparent mode. The configuration is just two 10GE links between our business partner dmz and our inside network. A simple map looks like this. 10.4.2.9/30 ...
6
votes
1answer
661 views

Passing Traffic through Traffic Management Device in transparent mode

We would like to pass traffic tagged (in the same vlan) from Router_1 to Router_2 throught a Traffic Management device (in transparent mode). Now, we are using two switches (running and aimed config ...
7
votes
3answers
13k views

Flow Control: to be or not to be?

We deploy two 3750-X switches in stack and connect Dell Storage to 10G-T ports. Dell recommends to use flow control on this ports, but some people have a lot of problems with this feature (packet loss,...
6
votes
6answers
2k views

Monitoring Network Traffic

I currently make use of a NETGEAR FVS338 firewall and a NETGEAR 24 port switch. Is there a way to graphically or in some way monitor their traffic? Edit: Switch Model FS726T
4
votes
1answer
2k views

CRC & Align Errors on D-Link switch, network down

I have network topology: (room 3) D-Link DES-1024D | | (room 2 MAIN) (room 4) Baseline 3COM Switch 2948-...
9
votes
3answers
3k views

Trying to test a virtual lab VRRP configuration for STP issues

I'm in the middle of setting up a lab with a VRRP configuration, and I'm trying to search for any possible issues we might run into in production. One issue I am aware of with VRRP is that it seems ...
14
votes
3answers
40k views

How to Monitor Vlan Traffic?

We have migrated to a new ISP who provide us several services (Internet+VoIP+VoD) and have divided each service in one vlan 100,101,102 respectively. Now I'm looking for a solution to monitor each ...
8
votes
1answer
2k views

Switch replacement procedure 3560G to 3750X

My company will upgrade two Cisco 3560G switches (an HSRP Active & Standby pair) to two Cisco 3750X switches in a stack. I need to make a switch replacement procedure starting from removal of the ...
5
votes
2answers
3k views

riverbed wan optimizer does not receive traffic

I have 2 Riverbed WAN optimizers and a WAN simulator. I connected 2 WAN ports of the 2 Riverbeds to the WAN simulator, connected 2 LAN ports along with 2 servers on a switch, and configured 2 subnets ...
6
votes
2answers
2k views

Cisco 7609-S Line card error counter is regularly exceeding threshold

I am receiving the following syslog messages on a 7609-S. Jun 17 11:52:27.560 BST: %CONST_DIAG-SP-4-ERROR_COUNTER_DATA: ID:47 IN:4 PO:255 RE:169 RM:255 DV:5 EG:2 CF:10 TF:472 Jun 17 11:52:27.560 BST: ...