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 am trying to get radius setup on this new switch,   Doing same thing I do for every switch. I get prompted to accept key, get the radius login and message but password not working.  Confirmed the secrets match with server.  I even have another 3548 I've copied exact. Not sure what I could have missed. Attached is config for another set of eyes
0
Hey all,

So I was asked to do something out of my realm and was wondering if someone could easily explain this to me.  Later I will be moving an access point from 1 location in someones office to another location, its basically unplugging it from 1 patch panel and installing it in another, however the trick is I need to move the configuration on the switch port to the new jack.   This is a Cisco POE switch.   Can someone tell me once I SSH/ Telnet into the switch how to move the port configuration then save it?  The new patch panel port would be A30 I dont know what the current patch number is but I have never done this before and do not want to mess anything up.   As always help is appreciated.
0
I'm running UCS 4.04 and I am not seeing in the GUI where port channels connecting upstream to the LAN are associated with which VLANs.
If I SSH to UCS I can see that the new VLANs I added on the server NICs appear to be (automagically?) appearing on the port channel to
the network. But if I go into LAN Uplinks Manager/VLANs/VLAN Manager I expecting to see the port channels underneath the VLANs with
which they are associated. But that is not the case. From nxos CLI note the VLANs and their association with the uplinks.Perhaps it's the case that if you don't specifically assign a VLAN to an uplink that all VLANs automatially are permitted on those uplinks?

Partial config from connect nxos:

vlan configuration 1,9-11,20,30,32
vlan 1,9-11,20,30,32


interface port-channel2
  description U: Uplink
  switchport mode trunk
  pinning border
  switchport trunk allowed vlan 1,9-11,20,30,32
  speed 10000
 
interface Ethernet1/1
  description U: Uplink
  pinning border
  switchport mode trunk
  switchport trunk allowed vlan 1,9-11,20,30,32
  udld disable
  channel-group 2 mode active
  no shutdown

interface Ethernet1/2
  description U: Uplink
  pinning border
  switchport mode trunk
  switchport trunk allowed vlan 1,9-11,20,30,32
  udld disable
  channel-group 2 mode active
  no shutdown

interface Ethernet1/3
  description U: Uplink
  pinning border
  switchport mode trunk
  switchport trunk allowed vlan 1,9-11,20,30,32
  udld disable
  …
0
I want to change the Vlan assignments on port 7 on an HP Switch.

Currently this port has no untagged vlans.  But it does have 2 x Tagged Vlans.

I think that was done by mistake and currently when I plug ethernet cable into that port no data comes from it.  I think the solution is to change 1 of the Vlans on that port to be untagged.

I hope it is as simple as:

>Vlan ##<enter>
>untagged 7<enter>
>write memory<enter>

Can anyone confirm?

Or should I
>vlan ##<enter>
>no tagged 7<enter>
>write memory
>unstagged 7<enter>
>write memory<enter>
0
I am working with a simple ACL, denying traffic to a subnet, outside of DNS services. However I am unable to get it to work correctly unless I use IP instead of TCP or UDP

The DNS server is a simple BIND server

This does not work:

ip access-list extended "Guest Vlan Access"
     10 permit udp 10.160.0.0 0.0.255.255 eq 53 10.10.4.21 0.0.0.0
     20 permit tcp 10.160.0.0 0.0.255.255 eq 53 10.10.4.21 0.0.0.0
     30 deny ip 10.160.0.0 0.0.255.255 10.10.0.0 0.0.255.255 log
     40 permit ip 10.160.0.0 0.0.255.255 0.0.0.0 255.255.255.255
   exit



This works but opens up more than I want:

ip access-list extended "Guest Vlan Access"
     11 permit ip 10.160.0.0 0.0.255.255 10.10.4.21 0.0.0.0
     30 deny ip 10.160.0.0 0.0.255.255 10.10.0.0 0.0.255.255 log
     40 permit ip 10.160.0.0 0.0.255.255 0.0.0.0 255.255.255.255
   exit


Ideas?
0
We have 2 units Fortigate 101 configure as HA Active-Passive ,both devices port 1 are connected to our one of the internal switch  but recently our switch is faulty and we will planning to buy 2 units stack the switch together to have redundancy.

Please advise to archive this i need to configure aggregation two port and configure POL in switch port ?Fortigate HA
0
We have a conference phone that needs to be moved around constantly where there is no ethernet jack.  Since our conference phone is a "wire only" phone, is it possible to locate a wireless hub that will connect to our router and then plug directly into the conference phone via an ethernet port?

Does such a thing exist and what's it called?
0
Hi guys,
I found this switch that will be potential candidate for my lab.
can you give me confirmation on the technical details?

24 rj45 Port Giga Ethernet ?
4 SFP (not SFP+) port ?
Possibility to add 2 modules of 2 SFP+ 10GB port each?
Layer 3 routing?

I don't understand what type of pci-e card + sfp module I need for my server or workstation
Thanks
0
I have a Cisco 2900 Series switch and I have CLI access to it, Ive been asked to provide firmware information of the switch, how can I pull that via the CLI?
0
What "Network device tracking software" do you recommend that will do something like https://www.solarwinds.com/user-device-tracker ?

Details
 1. Users =50
 2. VLAN = 1
 3. OS = Windows 10 Pro
 4. Switches = HP, willing to purchase NEWER models since mine are OLD
 5. Cost = under $500 if possible, but OK if more
0
Export File from 9300 Switch

Hi,

Cisco Tech is asking for the export of file from the switch. Need some directions on how to do this. Any help appreciated.

231     583844 Jan 06 2020 16:45:54.0000000000 +00:00 FKKS-Core_trace_archive_0-20200106-164554.tar.gz
0
I have several issues in my layer2 topology. This is a mixed switch environment (Dell and Cisco). Presently one of my Dell switches is the root bridge, and I want to promote the Cisco switch ( where my servers are attached) to the root bridge. I also have some protocol mismatches;
1. the cisco switches have LLDP, CDP and fast spanning tree running.
2. the dell switches have only spanning tree running.

I have ethernet ports flapping (going up and down) on every switch. What would be the best approach to clear these issues.
0
Info:
Aruba 3810
Vlans 801,802,803

Vlan 802 is our guest wireless subnet. I need to allow it to pull DNS from 801, pull dhcp from the switch, but not have any other access to 801 or 802 and go directly to the Internet, allowing all protocols. I only have access to the switch and am unable to test, so need to be sure I have things set up correctly. Does this accomplish what I need, based on the included config?

ip access-list extended "Guest Vlan Access"
     10 permit tcp 10.10.0.0 0.0.255.255 eq 53 172.17.0.0 0.0.255.255 log
     20 deny ip 10.10.0.0 0.0.255.255 172.17.0.0 0.0.255.255 log
     30 deny ip 10.10.0.0 0.0.255.255 10.13.0.0 0.0.255.255 log
     40 permit ip 10.10.0.0 0.0.255.255 0.0.0.0 255.255.255.255



Config:
vlan 801
   name "VLAN801"
   untagged 13
   ip address 172.17.1.2 255.255.0.0
   exit
vlan 801
   name "VLAN801"
   untagged 13
   ip address 172.17.1.2 255.255.0.0
   exit
vlan 802
   name "VLAN802"
   untagged 15
   ip access-group "Guest Vlan Access" out
   ip address 10.10.250.2 255.255.0.0
   dhcp-server
   exit

vlan 803
   name "VLAN803"
   untagged 16
   ip address 10.13.253.1 255.255.0.0
   dhcp-server
   exit

Open in new window

0
I have a Nexus 6k connecting to UCS Fabric Interconnect. What's puzzling to me is that there are are "jumbo packet" - millions of them counted in the sho interface commands. But the MTU on the Nexus side is 1500. And the same thing is true if I log onto the FI - I see jumbo packet counters highly incremented and yet the interfaces are all set to 1500 MTU. Any thought as to how I could be seeing these big counts of jumbo "packets" (Frames would have been a better term no?) when I don't think I have jumbo framing configured on either side of these links?

RTR01# sho int Eth 1/3
Ethernet1/3 is up
Dedicated Interface
  Belongs to Po2
  Hardware: 1000/10000 Ethernet, address: 002a.5cc2.4aca (bia 002a.5cc2.4aca)
  Description: TO-MY-UCS01-A
  MTU 1500 bytes, BW 10000000 Kbit, DLY 10 usec
  reliability 255/255, txload 89/255, rxload 4/255
  Encapsulation ARPA
  Port mode is trunk
  full-duplex, 10 Gb/s, media type is 10G
  Beacon is turned off
  Input flow-control is off, output flow-control is off
  Rate mode is dedicated
  Switchport monitor is off
  EtherType is 0x8100
  Last link flapped 4d02h
  Last clearing of "show interface" counters 17w1d
  1 interface resets
  30 seconds input rate 109418408 bits/sec, 19662 packets/sec
  30 seconds output rate 3958742016 bits/sec, 346160 packets/sec
  Load-Interval #2: 5 minute (300 seconds)
    input rate 166.25 Mbps, 24.08 Kpps; output rate 3.51 Gbps, 309.55 Kpps
  RX
    411181255573 unicast packets  8610632 …
0
I am using the Juniper migration tool but is this the best method when you are changing vendors from Cisco to Juniper as it relates to access switches. I need to be 100% accurate with the configs . Any suggestions much appreciated.
0
Hi.

I am setting up a SOHO.
Equipment is as follows.
1)  4 security cameras that record to the cloud through a Northern system
2)  Home wireless system mesh network
3)  Usual computers,  printers, etc
4)  Other "internet of things devices"  such as thermostats, lights.
5)  I have a total of 10 Ethernet jacks in our home, but only 6 in current use.

I will be installing a 19 inch 6U Wall Mount Patch Panel Bracket - 13.75 inch deep (also 24 port Cat 5E patch panel etc)
Gigabit internet.


I have concerns about putting all these things on one switch.  I like the idea of segmenting my network.  
I have heard good things about the Ubiquiti.  I am not an expert on routers, but I not a unfamiliar either.  
I am thinking about a router/switch capable of VLANS and POE for the cameras.  If I am misguided, then new insights are welcome.

With that in mind,  I would appreciate any help in selecting  a router / switch that would be appropriate but not more expensive than I need.

Thank you for your help.
0
How to backup the existing running configuration of Cisco routers and switches? So that l can load the configuration to another replacement device if failure
0
Hi,

I am trying to setup Hot standby DHCP server2012 (two DHCP server with multi-scope)
192.168.0.0
192.168.1.0
192.168.2.0
I am using two servers with fail-over DHCP configuration. (Hot standby) with IP address
192.168.0.1 for server 1 and 192.168.0.2 for server 2

In the Cisco 3750 switch I created 3 vlans
Vlan 10 with an IP address 192.168.0.3
Vlan 20  with an IP address 192.168.1.1
Vlan 30  with an IP address 192.168.2.1

In the configuration I added IP helper-address command to refer DHCP servers
Under each Vlan interface I added two IP helper address

Under Vlan 10
ip helper-address 192.168.0.1
ip helper-address 192.168.0.2

And so on for Vlan 20 and Vlan 30

The computers work fine and got IP address and getaway for each Vlan. However, I tried to test the fail-over DHCP and I shut down the DHCP server with an IP address 192.168.0.1 and waited to get computer an IP from second DHCP server but it's not working. I Release and renew IP and nothing changed.

Is there any missing part of my configuration?

Thanks
0
Hi,

I have Nec ITX-3370-1W(BK)TEL POE phone and when I attached it to Cisco 3750 POE switch the phone not working while when I attached Nortel 1120E or 1140E they are working.

Any idea to fix the problem?

Thanks
0
I'm experiencing a Linux routing problem.

Environment is SLES 12 SP2, running on some HP server machine with 8 physical, used network interfaces, running in a non-internet local network.

Most physical network interfaces (eth0 ... eth3 and eth5 ... eth7) have (local unique) static IP addresses in non-overlapping networks, and the routing table looks ok. The interface eth4 is on DHCP.

The problem is that sometimes packets seem to be sent over the wrong interface - a packet that is expected to fly thru eth6 is spit out on eth0. This happens erratic and causes to application software (managing measurement data) to loose the data stream after max ~15 minutes .

As fa s I can see,

  • the exit interface of the wrong-routed packets is always eth0
  • there are packets of at least 2 interfaces routed wrong
  • the configuration of eth0 (viewed by YaST and by inspection of /etc/sysconfig/network/ifcfg-eth0) shows no IP addresses from the other interfaces networks

If I take down eth0, the application runs smooth (but that's only acceptable for testing matters).

If I record the network traffic of the network addresses for eth2 (tcpdump), I find i.e. suspicious ARP requests originating from address on eth6 with an originating MAC address of eth0.

Any idea what happens here ?
Any idea how to fix it ?

P.S.: Due to some policies demands, I can't do any driver etc. updates on the system. Same appies to ideas like "do DHCP on all interfaces" ... I can't change that.
0
Restoring an Archive File to 2960

I can successfully transfer a file to and from my Cisco 2960 switch. I have an archive function in my configuration and it works great. I am trying to restore a config from my backup location to the flash on the switch. I can successfully SCP from the switch to my backup location and transfer the files to the switch flash. The file shows/ displays there. However, the file size on flash shows zero / 0.

I have verified the contents of the config in notepad. The file size, when viewed from computer, is 13 KB. I can open in notepad either using a .txt or .cfg extension.
0
Hi,

I have a HPE OfficeConnect 1950, I dont have the password and dont wont to lose the config. Can anyone please assist
0
Hi,

Our company internet provider set us up with a new modem which would deliver faster speeds and has the IBGP failover ability. In order to use the IBGP failover we would need to designate 1 (or 2?) IP's from our small block of IP's, or get rid of the current ones and use a larger block of IP's.

Does it make sense to just consolidate our current IP's instead of purchasing a larger block of IP's? We currently have 5 public (outside of the broadcast)

Is it best practice/ industry standard to purchase larger amount of public IP's?

Thank you.
0
Physical Parts of Control/Data/Management Plane.

reading about Control/Data/Management Planes , if I understand :

Control plane is where the Routing table is built.
Data Plane or also called Forwarding plane contains a copy of RIB
Management Plane , I am not sure what it is, probably it is just the interface of the router or the switch to which we connect to.

What I need to know, is the hardware that the above elements run on.

for instance does Control  plane encompasses CPU , Memory , or it is completely different Chip ? the same question applies for Data plane and Management Plane, on which hardware do they run on?

Thank you
0
Have two Dell powerconnect 5548's set up in a stack. Recently have been unable to login and when attempting ssh, I get the following error.
Remote side sent disconnect message - type 2 (protocol error): "Connection closed by server: Server reached maximum number of simultaneous connections

Open in new window

There seems to be a command for other dell switches to clear sessions however I am not seeing anything for the 5500x series. I set a session timeout and even rebooted the switch but I am still getting this error. All line connections show as locked in the web UI however reactivating the locked line through the GUI does not do anything. Anybody more familiar with Dell switches have an idea for how to resolve this error? I can currently manage the switch by console and web ui however it would be great to get remote ssh sessions running again.
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.