Go Premium for a chance to win a PS4. Enter to Win

x

Switches / Hubs

21K

Solutions

17K

Contributors

A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

Share tech news, updates, or what's on your mind.

Sign up to Post

I have  R1 that has learned EIGRP routes from R2  as shown below.



R1(config-std-nacl)#do sh ip route                
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, + - replicated route

Gateway of last resort is not set

      10.0.0.0/8 is variably subnetted, 7 subnets, 7 masks
D        10.1.0.0/16 [90/156160] via 192.168.12.2, 00:00:08, FastEthernet0/0
D        10.2.0.0/17 [90/156160] via 192.168.12.2, 00:00:08, FastEthernet0/0
D        10.3.0.0/18 [90/156160] via 192.168.12.2, 00:00:08, FastEthernet0/0
D        10.4.0.0/19 [90/156160] via 192.168.12.2, 00:00:08, FastEthernet0/0
D        10.5.0.0/20 [90/156160] via 192.168.12.2, 00:00:08, FastEthernet0/0
D        10.6.0.0/21 [90/156160] via 192.168.12.2, 00:00:08, FastEthernet0/0
C        10.10.10.10/32 is directly connected, Loopback10

I have this configuration below:
router eigrp 1
 distribute-list route-map FILTER_IN in 
ip access-list standard NET_1
 deny   10.0.0.0 0.0.255.255
route-map FILTER_IN permit 10
 match ip address NET_1

Open in new window


Now if I run sh…
0
Free Tool: Path Explorer
LVL 11
Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

When I add a debug to a 4500 switch at new work place, “show log” is failing to display my debug. Which logging command gets that going?
0
From my understanding "service password-encryption"  command encrypts all the password on the running config.  

How do you encrypt just the line con 0 password  ?
0
Hi Experts,

We have 20 Open Mesh Wireless Access Points in our building serving over 250+ Clients. Everything was running fine until we added 2 new SSIDs and tagged them on VLANs. These access points are connected to Netgear POE Switches and All these switches are connected to our Netgear Core Switch which is backed by iBoss (Firewall and Filtering) and Sonicwall (As a Router).

After we added two VLANs, our wireless network has been unstable since. We cant airplay to Apple TVs, Cannot connect our wireless computers / iPads to our 2 newly created SSIDs most of the time.

I did the VLAN for the first time and could be doing something wrong on that front. I have tagged the ports where i have access points connected and the ports that connects to the core switch. On Core Switch, i have tagged the ports that connect these switches and the port that connects with the iBoss.

Please let me know if you need any additional information on this issue.
0
We have ten gigabit interfaces. How much tunneled traffic would the device be able to push?
0
Does the user name to access Cisco switch configured on line VTY?
0
Hi all,

Please can anyone suggest any free simple text editor that can compare two different cisco config side-by-side


Thanks
0
Hi all,

Is there a command similar to "access-class management-acl in vrf-also" on the Cisco NX-OS platform?

Thanks!
0
We are using GS748Tv4 switch on our network and for last couple of days it blocks few ports on the switch for no reason and we have to do reset on the switch to again reactivate all the ports, we have turned off the spanning tree on the switch and its running on firmware 5.4.2.13, any advise would be helpful.

Also today when I logged on to the switch interface it showed "tftp file transfer in progress" on all screens.
0
I have at some locations cisco ap 1142. Using this link:https://www.cisco.com/c/en/us/td/docs/wireless/compatibility/matrix/compatibility-matrix.html

I see that cisco 1140 series is not listed under software version 8.4.100.0 or above. Do we have to replace these access points with newer ones? We cannot upgrade the software for the controller to 8.4.100.0 or above until we replace the access points? Please advise.
0
Ask an Anonymous Question!
LVL 11
Ask an Anonymous Question!

Don't feel intimidated by what you don't know. Ask your question anonymously. It's easy! Learn more and upgrade.

Dear Experts, we could not connect to a Web server from a LAN network range, other ranges are OK. What should we check?
Environment: Cisco switch 2960, 3750/3560, router 3925, Window Server 2008R2

Many thanks in advance,
0
Dear Experts, we noticed that some times, the bandwidth of Router is high but not sure its reasons. How can we check which application or somethings are consuming the bandwidth in LAN network?

Cisco Router 3925, Core switch Cisco 3750/3560, Access switch Catalyst 500, 2960
0
Hi,

I am getting the following error on switch, kindly suggest how we can resolve this issue

switch: boot
Loading "flash:c2960x-universalk9-mz.152-2.E7.bin"...flash:c2960x-universalk9-mz.152-2.E7.bin: no such file or directory

Error loading "flash:c2960x-universalk9-mz.152-2.E7.bin"

Interrupt within 5 seconds to abort boot process.
Boot process failed...

Regards,
Naresh
0
Hi, Anyone can take a look at the commands and snmp-server enable traps snmp linkdown linkup. I do not know why it cannot work. Do you think the configuration on it is correct? Please see the below

MySW(config)#do sh run | i snmp
snmp-server community TSHOOT RO
snmp-server location Amsterdam
snmp-server contact info@networ.com
snmp-server enable traps snmp linkdown linkup
snmp-server host 10.0.0.123 version 2c TSHOOT

The switch and PC(Solarwinds installed) can ping each other.  Ip address 10.0.0.123 is the PC ip address to connect to the switch. Solarwind can see the switch. But the issue is after several interfaces are shutdown in switch, why no any change can be seen on Solarwind side?
0
Hi there,

i bought ADVA FSP 3000R7 for cheap and need advise on how to reset the unit to Factory defaults.

I have connectet the Serial Console but i cannot interupt the Boot Secuence unless i remove the compact flash cart.

It would be perfect if someone could List me the Steps. Otherwise the usermanual would be awsome.

Thanks allot.

Best regards
0
can someone help why the below commands doesn't work?

xxx#

xxx#del flash:c3560e-universalk9-mz.122-53.SE2

Delete filename [c3560e-universalk9-mz.122-53.SE2]?

Delete flash:c3560e-universalk9-mz.122-53.SE2? [confirm]

%Error deleting flash:c3560e-universalk9-mz.122-53.SE2 (Is a directory)

xxx#Delete /force/recursive flash:c3560e-universalk9-mz.122-53.SE2

                      ^

% Invalid input detected at '^' marker.

 

xxx#Delete /force/recursive flash:/c3560e-universalk9-mz.122-53.SE2

                      ^

% Invalid input detected at '^' marker.

 

xxx#rmdir flash:c3560e-universalk9-mz.122-53.SE2

Remove directory filename [c3560e-universalk9-mz.122-53.SE2]?

Delete flash:c3560e-universalk9-mz.122-53.SE2? [confirm]

%Error Removing dir flash:c3560e-universalk9-mz.122-53.SE2 (Directory not empty)

xxx#



xxx> dir flash:
Directory of flash:/

    2  -rwx        8716  Aug 24 2016 14:58:09 -05:00  config.text
    3  -rwx        4120  Aug 24 2016 14:58:09 -05:00  multiple-fs
    4  -rwx    14581903  Mar 15 2013 20:12:53 -05:00  c3560e-universalk9-mz.122-55.SE5.bin
    5  -rwx        3816  Aug 24 2016 14:58:09 -05:00  private-config.text
    6  drwx         512  Feb 28 1993 18:15:07 -06:00  c3560e-universalk9-mz.122-53.SE2
0
Hi experts!

I'm having a weird issue with multipathd and device-mapper, when SPA goes down/rebooted path doesn't seem to properly failover to SPB on CentOS. Both of my iSCSI paths are available to a CentOS 7.4 server, one is active while the other is enabled in case of failover. As you can see below:

[root@oracledb1 ~]# multipath -ll
ORACLEREDO (360060160cec14400fd2f9259dbd7810a) dm-3 DGC     ,VRAID
size=20G features='1 retain_attached_hw_handler' hwhandler='1 alua' wp=rw
|-+- policy='round-robin 0' prio=50 status=active
| `- 34:0:0:2 sdd 8:48 active ready running
`-+- policy='round-robin 0' prio=10 status=enabled
  `- 33:0:0:2 sde 8:64 active ready running
ORACLEDATA (360060160cec14400022e9b5993b6e77f) dm-4 DGC     ,VRAID
size=2.0T features='1 retain_attached_hw_handler' hwhandler='1 alua' wp=rw
|-+- policy='round-robin 0' prio=50 status=active
| `- 33:0:0:4 sdg 8:96 active ready running
`-+- policy='round-robin 0' prio=10 status=enabled
  `- 34:0:0:4 sdf 8:80 active ready running
ORACLEARCHIVE (360060160cec14400b7939359675bc79e) dm-2 DGC     ,VRAID
size=500G features='1 retain_attached_hw_handler' hwhandler='1 alua' wp=rw
|-+- policy='round-robin 0' prio=50 status=active
| `- 34:0:0:0 sdc 8:32 active ready running
`-+- policy='round-robin 0' prio=10 status=enabled
  `- 33:0:0:0 sdb 8:16 active ready running

Open in new window


Our storage array is a EMC Unity300 and the switch is a Nexus3k with 2 trunk ports to the storage array (iSCSI), 1 port to SPA and 1 port to SPB.

While testing iSCSI failover I noticed that when I reboot SPA (controller A) of the storage array, our Oracle database failed due to the 3 iSCSI disks above not being reachable on the second path (SPB, controller B).

I see session for both iSCSI ports.
[root@oracledb1 ~]# iscsiadm -m session -o show
tcp: [1] 172.29.11.66:3260,1 iqn.1992-04.com.emc:cx.apm00171401013.b2 (non-flash)
tcp: [2] 172.29.11.65:3260,2 iqn.1992-04.com.emc:cx.apm00171401013.a2 (non-flash)

Open in new window


Here are the versions:
[root@oracledb1 ~]# rpm -qa |grep device-mapper
device-mapper-multipath-libs-0.4.9-111.el7.x86_64
device-mapper-1.02.135-1.el7_3.5.x86_64
device-mapper-libs-1.02.135-1.el7_3.5.x86_64
device-mapper-event-libs-1.02.135-1.el7_3.5.x86_64
device-mapper-multipath-0.4.9-111.el7.x86_64
device-mapper-event-1.02.135-1.el7_3.5.x86_64
device-mapper-persistent-data-0.6.3-1.el7.x86_64

Open in new window


Here's my multipath configuration:

Open in new window

0
I'm getting these errors, and I kind of understand why, but  I guess I might need some help in knowing how to configure the ports so they go away.
vlanmismatch
here's a small portion of my current network setup
current setup
here's how the network should be, as I have to install more cameras and use a POE switch.
proposed setup
I'm guessing I'll still continue to get those errors even with the new setup?
How do I need to configure those few switches so I don't get those errors?
The two switches with vlan 800, I only need to connect to them for management, and monitoring. I don't need and don't want any of that traffic to traverse my vlan1 network.

Any thoughts of what I'm doing wrong?
0
Just had someone mention that the network version of  quickbooks was sluggish & here's what task manager tells me about traffic,.
Everything is gigabit ethernet, so why is this so slow?Net-traffic.JPG
0
Important Lessons on Recovering from Petya
LVL 11
Important Lessons on Recovering from Petya

In their most recent webinar, Skyport Systems explores ways to isolate and protect critical databases to keep the core of your company safe from harm.

I have hsrp for gateway redundancy for my fw1. wan1 and wan2 router have hsrp configured with the virtual hsrp 1.1.1.1. Currently. as you can see from the diagram, if sw1 fails, I have to manually move the cables to sw2. How would I make sw2 the backup for sw1? Thx

pic
0
Hello,

I have a switch where the files in flash were deleted so it won't boot. I found a copy of the files and attempts to upload them via xmodem. The issue i seem to be having is as soon as the file is uploaded is automatically renames is to default_file. When I try to set the file as the app it does not show it as an option. every file i upload it wants to save as default file.
0
Hi,

I have a few electronic devices in a room which do not need to be on when there is nobody in the room.

The times are variable for when people would be in the room.

These devices are plugged into an extension lead which I would like plugged into a sensor socket.

Ideally what I would like is for when someone walks in the room, the sensor socket would switch on and the devices would in turn switch on too.

The opposite would happen when someone leaves the room for a few minutes.

I would like one that does not require a hub or Wi-Fi as I would have a switch connected to this sensor socket.

Also, it would be an advantage if the sensor socket did not turn off if people were sitting down watching TV but not making much movement.

What would you recommend?

Thanks,
Robbie
0
Hello there.  I am wondering If I can use old IBM QLE2460 cards, fiber channel with a switch, like brocade 300 to emulate ethernet connections of 4GB.
In the same manner, I am wondering If I can HP 10GB MELLANOX CONNECTX-2 cards ( windows 2012R2 of windows 10) with a switch like  Mellanox MIS5025Q-1SFC to emulate 10GB connection. Also, it would be fantastic if there was ESXi 6.x support for this. Please advise!!!!  Are there any limitations that I would be aware???

Ps. When I say emulate I mean to use Fibre or Infinity band to work as ethernet with proper drivers and switch configuration.
0
Hi ALL,

We're trying to plug in a phone into a switch that is primarily used for data but was configured for data and phone, however, when the phone is plugged in it does connect to the network. Below is config from the data switch configured for data and phone and a switch configured for only phones ( or at least that what we use it for).  Please let me know. Thank You.

Switch configured for use with phones - both data and phone work

interface FastEthernet2/0/39
 switchport access vlan 10
 switchport voice vlan 20
 srr-queue bandwidth share 10 10 60 20
 srr-queue bandwidth shape  10  0  0  0
 mls qos trust device cisco-phone
 mls qos trust cos
 auto qos voip cisco-phone
 spanning-tree portfast

Switch configured for DATA - Only Data works (what do we have to configure for phones to work?)


interface GigabitEthernet3/0/46
 switchport access vlan 10
 switchport voice vlan 20
 spanning-tree portfast
0
Hi Guys,

I'm looking after a site that has one or two bandwidth problems.  Topology is as follows:

It has a couple of Cisco 2950 switches and a Cisco 3560 switch which is configured to have a few VLANs.  Due to the geographical location of the site, internet lines are poor.  We have two gateways (30mb an 16mb) on this site and I have configured PBR to give a certain amount of load balance.   The gateways themselves are just the standard Netgear/D-Link type routing devices.

We are finding at certain times the bandwidth is much slower than we would expect and suspect one of the vlans is the culprit.  I'm going to setup SPAN on the port of the gateway the VLAN is using, then sniff and monitor the traffic.  I'm pretty sure what I'll find.  

So my question is.  What is the best way to limit the ingress and egress traffic from a particular VLAN from the 3560 switch.  I'm not bother about traffic type, just want to limit ALL inbound and outbound traffic to a specific rate.

I'm not sure if it's possible or feasible.  Have seen lots of stuff about rate-limit and policing etc, but nothing definitive.  I'm trying to avoid changing the topology too much by perhaps sticking in a Cisco router or swapping out the Gateway boxes for something that can handle more of the Enterprise type options.

What do you think?  I'm I flogging a dead horse, or do I need to change the topology.

Thanks for your help guys
0

Switches / Hubs

21K

Solutions

17K

Contributors

A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.