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Switches / Hubs

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Solutions

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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.

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Everyone has always said HUBs are bad and send information to ALL devices

I have an employee that needs another PC setup next to them ASAP and I do not have time to run another 100' CAT6 cable from the switch to this PC, therefore I just setup a small $10 cheap hub as follows

 1. patch cord from SWITCH to HUB
 2. patch cord from HUB to PC #1
 3. patch cord from HUB to PC #2

Which one of the below options will happens since a HUB is now in the mix when PC #2 updates a file on the Windows 2012 R2 file server since I did not wire back to the Cisco switch ?

    ** Option #1 = PC #2 sends info to ALL 100+ devices on my network, with only the file server accepting the data

    ** Option #2 = PC #2 sends info to ALL devices that are plugged into the hub (i.e. only PC #1 and the switch), with only the file server accepting the data

   ** Option #3 = something else ?
0
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I have EIGRP routes advertised from R1 to R2 as shown below:

R2#sh ip route eigrp 1      


      10.0.0.0/8 is variably subnetted, 13 subnets, 7 masks
D        10.10.10.10/32 
           [90/156160] via 192.168.12.1, 00:00:09, FastEthernet0/0
      20.0.0.0/32 is subnetted, 1 subnets
D        20.20.20.20 [90/156160] via 192.168.12.1, 00:00:09, FastEthernet0/0
      172.16.0.0/16 is variably subnetted, 5 subnets, 3 masks
D        172.16.0.0/24 [90/156160] via 192.168.12.1, 00:00:09, FastEthernet0/0
D        172.16.2.0/24 [90/156160] via 192.168.12.1, 00:00:09, FastEthernet0/0
D        172.16.3.0/24 [90/156160] via 192.168.12.1, 00:00:09, FastEthernet0/0
D        172.16.12.0/22 
           [90/156160] via 192.168.12.1, 00:00:09, FastEthernet0/0
D        172.16.22.0/26 
           [90/156160] via 192.168.12.1, 00:00:09, FastEthernet0/0
R2#

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on R1 I have configured route map and prefix list to block (filter out)network 172.16.0.0 /16 le 26,  but it does not seem to work

route-map FILTER_OUT deny 10
 match ip address prefix-list SMALL_PREFIXES
ip prefix-list SMALL_PREFIXES seq 10 permit 172.16.0.0/16 le 26

route-map FILTER_OUT permit 20

Open in new window


Any Help ?

thank you
0
Hi, is there a way to update the ProCurve 2510G so it won't use Java in the GUI? And yes, I know, there is the CLI and I'm using that one already too. Just wondering for the web interface. Sometimes it might come in handy. But it's hard to get it working in any current browsers apparently ...

Thank you
0
does "switchport mode trunk" command allow all vlan by default or I do I need to issue "switchport trunk allowed vlan all" ?
0
I need to add a route to our ProCurve switch which will allow all traffic from my network destine for a network in our parent company.

All traffic from 192.168.0.0/21 going to 172.20.0.0/16 needs to go thru (edge router)192.168.0.150

My parent company sent me the edge router and setup a VPN tunnel using this device, which has the 192.168.0.150 interface. The VPN is working as If I add the command  "route ADD 172.20.0.0 MASK 255.255.0.0 192.168.0.150" to my computer I am able to reach the server at our parent company.

Not sure how to add the route to the ProCurve
 

Below is the config for my ProCurve

hostname "ProCurve 2910al-24G Switch"
time timezone -300
time daylight-time-rule Continental-US-and-Canada
module 1 type J9145A
ip default-gateway 192.168.0.3
ip routing
vlan 1
   name "DEFAULT_VLAN"
   untagged 1-12
   ip address 192.168.0.3 255.255.248.0
   no untagged 13-24
   exit
vlan 2
   name "OSAI"
   untagged 13-24
   ip address 10.10.10.8 255.255.255.0
   exit
timesync sntp
sntp unicast
sntp server priority 1 192.5.41.41 3
ip route 0.0.0.0 0.0.0.0 192.168.0.8
snmp-server community "public" unrestricted
snmp-server contact
0
Network
In the topology above , I have EIGRP configured on both routers.
I have advertised all the networks to EIGRP

these are the interfaces in R2:
R2(config-router)# do show ip interface bri
Interface                  IP-Address      OK? Method Status                Protocol
FastEthernet0/0            192.168.12.2    YES manual up                    up      
FastEthernet0/1            unassigned      YES unset  administratively down down    
FastEthernet1/0            unassigned      YES unset  administratively down down    
FastEthernet1/1            unassigned      YES unset  administratively down down    
Loopback0                  172.16.0.2      YES manual up                    up      
Loopback1                  172.16.1.2      YES manual up                    up      
Loopback2                  172.16.2.2      YES manual up                    up      
Loopback3                  172.16.3.2      YES manual up                    up      
R2(config-router)#

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in R2 , when I advertise R2(config-router)#network 172.16.0.0 0.0.3.255
I do not get any error, and all 172.x.x.x networks will show up in R1 routing table:

R1#sh ip route  eigrp 

Gateway of last resort is not set

      172.16.0.0/24 is subnetted, 4 subnets
D        172.16.0.0 [90/156160] via 192.168.12.2, 00:02:02, FastEthernet0/0
D        172.16.1.0 [90/156160] via 192.168.12.2, 00:02:02, FastEthernet0/0
D        172.16.2.0 [90/156160] via 192.168.12.2, 00:02:02, FastEthernet0/0
D        172.16.3.0 [90/156160] via 192.168.12.2, 00:02:02, FastEthernet0/0
R1#

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but if I try different wild card mask I get error  :
R2(config-router)#network 172.16.0.0 0.0.4.255
%EIGRP: Invalid mask (discontiguous)

but if I try these wild card masks one a time after Negating one of them , it will work:
R2(config-router)#network 172.16.0.0 0.0.1.255
R2(config-router)#network 172.16.0.0 0.0.0.255  

***So the ones that worked (one a time) are:
R2(config-router)#network 172.16.0.0 0.0.1.255
R2(config-router)#network 172.16.0.0 0.0.0.255  
R2(config-router)#network 172.16.0.0 0.0.3.255

the :172.16.0.0 0.0.2.255 ,172.16.0.0 0.0.4.255,172.16.0.0 0.0.5.255........172.16.0.0 0.0.254.255

I get this error :%EIGRP: Invalid mask (discontiguous)

Any idea why  ?

Thank you
0
I have ext 213 which is BD3 Port 7. I need to move the line to a different port in the office. We have a patch panel and I have a intelli probe. All I should have to do is take the wire from BD3 Port 7 and move it to the proper spot on the patch panel (where new outlet will be)?

I’m trying to learn the phone system, I was able to setup a different line but this one is being difficult.
0
Hi Guys,

I had to switch our two WAN Interfaces on SonicWALL, (Thus X1 & X2)

1.  I switched the public IP configuration under Interface Settings
2.  and changed all the NAT policies, switching X1 & X2 for all rules


My questions,

a.  Is there any other rule(s) that need to be changed to switch primary internet access for LAN users between X1 & X2?

b.  I've noticed that some NAT rules refer to an "address object" rather than the interface (X1/X2) directly.  
These I did not change as the object's public address was still correct.  Is there a difference in referring to the interface (X1/X2) directly, or using an object instead?  
In my case, where I had to switch X1 & X2 ... the rules with objects made things a bit easier as it stayed the same.  Is this the only difference using an object or referencing to the interface directly?
0
Dear all, We have 5-6 HP 1950 switches with weird OS, which does not allow friendly and commonly used CLI commands as the HP 2920 or Cisco IOS for that matter. 

We have an overly complicated network with 5 VLANS, we are attemtping to clean the VLANS and eliminate some. In the process we are attempting to configure the switches in a way where VLANs are assigned auto based on the device connected to the port (or MAC address for that matter). For example, if its a Mitel phone than the phone will be assigned the VoiP VLAN/ network. If its a PC then the LAN VLAN. 

Our phones are all Mitel 5360s. DHCP is done on a Meraki MX84 firewall, with the exception of the LAN, which is done on the DC/AD. 

Any ideas how to achieve this on the 1950s? Can this be implemented on other VLANs/ devices such as A/V VLAN with cameras and other devices or just Voice/ VoIP VLANs?

Many thanks for your help. 
0
Need to connect cable modem to 8-port POE switch but neither has DHCP Service, necessitating the possible need for a router. Need simple Plug&Play P&P.  Do not need WIFI, since this will be remotely located and wired to POE switch.  Effectively, I need a router w one WAN and one LAN port and with DHCP service.  This goes in a 24" high structured wiring panel.  The switch is a Netgear GS108PE 8-port POE Gigabit Smart Managed Plus Switch.
0
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We have an HP 2920-48 port POE switch. We also have 2x HP 2920-48 port NON-POE switches. I was surprised to find today that our new VOIP phones are actually get power when plugged into the NON-POE switch?! Is this possible?? If so, are there possible issues I should consider when configured in this manner. I know we are having issues with the phones losing calls before they can be answered...wondering if related.
0
I want to connect together six of HPE 1950-48G-2SFP+-2XGT switches. Looks like the maximum number that can be stacked together with the IRF stacking system is four – so there’s too many switches to stack.

I don’t want to buy the fiber modules.
I want to connect each switch via the 10Gb connections, with redundancy for the other switches if one fails.

I’m thinking to connect them in a ring like this –

Switch 1 10G port A to Switch 2 10G port B
Switch 2 10G port A to Switch 3 10G port B
Switch 3 10G port A to Switch 4 10G port B
Switch 4 10G port A to Switch 5 10G port B
Switch 5 10G port A to Switch 6 10G port B
Switch 6 10G port A to Switch 1 10G port B

Would that work?

Any other configuration changes I need to make, eg enable MSTP to deal with the loop, LLDP etc?

Thanks
0
EIGRP Lab example for Query Scoping.

I have read about EIGRP Scoping , and in most of articles they recommend Summarization at the Edge router. I have tried that, and enabled Debug EIGRP Packets Query on other routers, and shut down interface on one of the routers behind the Edge router, but I still saw a Query sent by the Edge Router to other routers.

I am not sure if that's normal behaviour or the lab is not the right set up to test EIGRP Query Scoping.

Any Lab Example from EIGRP Expert that demonstartes EIGRP Query Scoping might  help understand this topic..

Thank you
0
When does EIGRP Equal Load-Balancing happen

I have managed to Test Unequal load-balancing using Traceroute multiple times and quickly.

However for Equal Cost , I tried Traceroute multiple times and quickly , but it keeps going through one path..

I am not sure now if Equal Cost Load-balancing happens only when there is congestion on one path...if so why this does not happen on Unequal Cost..

Any Clarification will be very much appreciated.

Thank you
0
I have cisco 3650-48FQ-S that has 4 sfp+ ports. I have 3504 Cisco WLC with one 10G RJ-45 port. Do 10GBase-T sfp+ copper Transceiver works/compatible with 3650 sfp+ port to connect to 3504 10Gig RJ-45 copper port? What is the part# to buy?
0
I dont know why I'm having this issue but it's happenig. I am working on basic topology. Router to layer 3 switch to little trendnet L2 switch to hosts. Image attached. Very simple. For some reason, the switch in the middle, STP is blocking the port. I have no idea why. How can I fix this and why it this even blocked, there is no redundant links
map.png
interface GigabitEthernet0/4
 switchport access vlan 100
 switchport mode access
 switchport nonegotiate
 switchport port-security maximum 4
 switchport port-security violation restrict
 switchport port-security aging time 60
 switchport port-security aging type inactivity
 switchport port-security
 no keepalive
end

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TEST_SW#sh spanning-tree blockedports

Name                 Blocked Interfaces List
-------------------- ------------------------------------
VLAN0100             Gi0/4

Number of blocked ports (segments) in the system : 1

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There is no even loop. It's one link to the L2 switch thats all.

Can anyone help that actually know whats going on here? Lately I've been getting a lot of answers that were useless to me and did not help. Thank you
0
eigrp
I have configured EIGRP on all routers.
From R1 I can see there are 2 unequal paths to get to 4.4.4.4 loopback on R4, that 's after I used Variance command.

R1#sh ip eigrp topology 
EIGRP-IPv4 Topology Table for AS(1)/ID(192.168.13.1)
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
       r - reply Status, s - sia Status 

P 192.168.24.0/24, 1 successors, FD is 30720
        via 192.168.12.2 (30720/28160), FastEthernet0/0
P 192.168.34.0/24, 1 successors, FD is 33280
        via 192.168.12.2 (33280/30720), FastEthernet0/0
        via 192.168.13.3 (261120/28160), FastEthernet0/1
P 192.168.12.0/24, 1 successors, FD is 28160
        via Connected, FastEthernet0/0
P 4.4.4.4/32, 2 successors, FD is 158720
        via 192.168.12.2 (158720/156160), FastEthernet0/0
        via 192.168.13.3 (389120/156160), FastEthernet0/1
P 192.168.13.0/24, 1 successors, FD is 258560
        via Connected, FastEthernet0/1
        via 192.168.12.2 (35840/33280), FastEthernet0/0

R1#

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R1#sh ip route eigrp    
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

      4.0.0.0/32 is subnetted, 1 subnets
D        4.4.4.4 [90/389120] via 192.168.13.3, 01:04:06, FastEthernet0/1
                 [90/158720] via 192.168.12.2, 01:04:06, FastEthernet0/0
D     192.168.24.0/24 [90/30720] via 192.168.12.2, 01:04:06, FastEthernet0/0
D     192.168.34.0/24 [90/33280] via 192.168.12.2, 01:04:06, FastEthernet0/0
R1#

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I tried Traceroute, but realized it will use just one path , even when I use that command over and over :Traceroute 4.4.4.4

R1#traceroute 4.4.4.4

Type escape sequence to abort.
Tracing the route to 4.4.4.4

  1 192.168.13.3 16 msec 52 msec 12 msec
  2 192.168.34.4 24 msec 28 msec 44 msec
R1#

Open in new window


the only time it took the other path through R2, is when I cleared EIGRP neighborship
R1#clear ip eigrp neighbors

it worked just one time though...

I am not sure if   Load-Balancing is working , but I am not using proper command to test, or it is not working...

Any help ?

Thank you
0
Hi
Can we configure ESW-540 switch as a DHCP server with it's own address pool? Have already reviewed the manual but it doesn't seem to have this functionality.
0
We have a shared DR site with our parent company and we are currently on the same subnet (192.168.200.0/24).  Both of our production sites are in separate physical locations with a point to multi-point metro-ethernet link between the sites.  I'd like to segragate our servers from the parent company and place them on a separate subnet at the DR site.  

I'm including the config below that is relevant to my situation.  My production site is "Switch 1", the DR site is "Switch 2" and the firewall is at the DR site.  

At the DR site, I can either use the switch for layer 3 by configuring an IP (192.168.206.1) on interface vlan 206, or the firewall using 192.168.206.254.  My thought is that it would be more secure using the firewall, I'm not really seeing additional latency.  If I use the switch, I would need vlan 206 to use a different default route than vlan 200, which I don't think is possible.  Our parent company will remain on the 200 VLAN using 192.168.200.0/24.  My question is, I have it working using the firewall for routing as the default gateway of my servers on vlan 206, but am I configuring this in the most ideal way?  Thanks.

Switch 1 (Production site)

interface Vlan210
  ip address 192.168.210.2 255.255.255.0
 
ip route 192.168.206.0/24 192.168.210.1


Switch 2 (DR site)

interface Vlan210
 ip address 192.168.210.1 255.255.255.0

interface Vlan206
 ip address 192.168.206.1 255.255.255.0

interface Vlan200
 ip …
0
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Hello,

I am playing around with DHCP Snooping on a switch before I deploy the config out. I have a very simple lab. Router that provides DHCP to a switch with a host on it. I enabled DHCP snooping on my vlan and on the switch

IT_SWITCH#sh run | i snooping
ip dhcp snooping vlan 1
ip dhcp snooping

Open in new window


No trusted ports have been configured on any port even the trunk to the router so technically, I shouldn't get DHCP IP address to my host? Correct? If so, I am. Am I doing something wring? No trusted port was configured so I should not get dhcp
0


R4 has Loopback 0 4.4.4.4 in area 0
other physical interfaces as shown in the topology they are in area 1,2,3


I have configured on R4:
R4#sh run | beg ip prefix
ip prefix-list INTO-AREA3 seq 5 deny 2.2.2.2/32
ip prefix-list INTO-AREA3 seq 10 permit 0.0.0.0/0 le 32
ip prefix-list INTO-AREA3 seq 15 deny 192.168.14.0/24
ip prefix-list INTO-AREA3 seq 20 deny 192.168.24.0/24

router ospf 1
 area 3 filter-list prefix INTO-AREA3 in

when I go to R3 I see the routes below still there when they should be filtered out:
192.168.14.0/24
192.168.24.0/24

I have changed the sequence number of this command to sequence 25:
ip prefix-list INTO-AREA3 seq 25 permit 0.0.0.0/0 le 32

and now I see the filtering worked. When I go to R3 which is in area 3. I do not see the routes:

192.168.14.0/24
192.168.24.0/24

Any Expert to explain the logic that the route has used in regard to the  ip prefix-list sequences. ?

Thank you
0
I have been troubleshooting an issue of some voip problems at a site. A colleague who's now left mentioned he had run into some spanning tree issues that had caused problems. He fixed that problem he said by adding "portfast" to the access switches. I'm seeing most of these ports set to port type "access" and BPDU guard is set. But I want to verify that changes in spanning tree are not happening which might affect traffic. Are there command that would let me see recent spanning tree change events? Or would I only be able to see this with debug?
0
Is there any way to show interfaces on an IOS Cisco switch which only have x number of input errors? crc errors?

I tried to use "show int | i error" and that showed me lines with the word error but left me with no way to see with what interface the errors were associated.

Thank you.
0
What are the best types of 5 port POE switches that can have Comcast Power over Ethernet (POE) phones plugged into them?

An office where I work with have two Comcast POE phones but has only one Ethernet port. We need to connect a switch to it so we can plug in both of the Comcast POE phones as well as two laptops.

What are the best types of switches for this?
1
I have this config on cisco 3650 switch:
enable secret 5 $1$CjMf$vnUDcs1IGZSNACW
enable password 7 03124C0F0F5E79
!
username admin privilege 15 secret 5 $1$8zl1$kGUgJ5pHTOyz2
username tech privilege 15 secret 5 $1$QsH.$G.R4BJBhZh6K6jA

when I telnet it asks for username and password. When I enter username and password  it goes directly to: #_

How to go to: >_ and then to ask for another password?
1

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.