Questions tagged [switchport]

For questions about switchports on network devices. For instance, you want to configure a trunk on a router interface or you are wondering how you setup an interface on a switch for a server.

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5
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2answers
286 views

What is the springing mechanism for on the top of this transceiver module?

Some Ethernet SFP modules have them, some do not. What is the yellow springing mechanism and the attached metal wire meant for?
5
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2answers
1k views

What's the `line protocol` and `Link`?

When I show a switch interface information, there are line protocol and Link: Switch-A(config-if)# show interface gigabitethernet 0/3 Gi0/3 up, line protocol is up (connected) Bridge Port Type: ...
4
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1answer
718 views

MAC Address learning process

Does a switch learns hosts mac address in these following scenarios: Switch port configured as access and frames received tagged on different VLAN Switch port configured as trunk and frames received ...
4
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3answers
959 views

JunOS, access mode interface asks for a vlan

I'm kinda new to networking so I'm going to do my best to try explain my issue. The issue that I have is that I want to delete all default configuration for my xe interface. Current configuration: ...
4
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1answer
878 views

Best Practice for Voice and Data VLAN on single port

We have multiple interfaces currently configured with the below on our Cisco 3750x switch. interface GigabitEthernet1/0/21 switchport access vlan 4 switchport trunk encapsulation dot1q switchport ...
4
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1answer
325 views

Port Channel Hybrid Port Issue

I have a Dell Sonicwall NSA 4600 running the latest firmware with an Interface that's configured to have a secondary redundant port. This interface also has a VLAN sub interface assigned to it. On ...
3
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1answer
173 views

cisco switchport trunk native vlan

we have switch catalyst 3850 and we need to enable the PXE boot on a port configured in trunk with configured three VLAN (4040, 4050 and 4060). To permit the PXE boot and deploy to work we set on the ...
3
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2answers
2k views

HP switch "No untagged port"

A network engineer showed me the show vlan output of an HP switch. I know tagged ports are trunk and untagged ports are access in Cisco terms. But can anyone explain the "no untagged port"? How is ...
3
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3answers
2k views

Forwarding to multiple output ports using SDN

Using switches that support OpenFlow, is it possible to forward packets for specific flows to multiple outgoing ports, so that each port receives a copy of the packet (similar to multicasting scenario,...
3
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1answer
396 views

Save switch config in USB

I want to save the configuration of an Avaya 4850GTS-PWR+ switch in a usb stick So I plug the usb in the switch Connect to the switch via putty using the Serial port in my laptop to the RJ45 Console ...
3
votes
1answer
630 views

Isolating ports on a Cisco Catalyst 2960-X Switch

I'm a bit of a newbie when it comes to networking, so excuse my ignorance for asking this. I did try to post this on the Cisco support forums, but kept getting told it was spam haha, so I hope this is ...
3
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0answers
49 views

Are there any of NX-OS switchport "meta tags" alike features?

I believe I once stumbled across an NX-OS feature which we currently need, but for the sake of it, I can't remember the details like platform (100V, 5000, 7000) or version. We are currently using 5600'...
3
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0answers
297 views

HP 5500 JD374A Port naming convention

Hi to all :) To most of you it'll prolly sound like a very silly question to ask, however to me as a fresh network trainee the answer is unfortunately not so obvious. So, the question is whether the ...
2
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3answers
2k views

Can VLANs with same no but on different switches communicate with each other?

If i have a VLAN (say VLAN 10) on switch 1 and again a VLAN 10 on switch 2. Can the hosts on these VLANS communicate with each other?
2
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2answers
170 views

How does a Layer 2 Switch know which port is a neighboring switch port and which port is connected to a host?

I want to know what is the mechanism behind a switch, so that it understands which of its ports are connected to a host (end device), and which of them are connected to another switch? Imagine trunk ...
2
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3answers
105 views

can i check the ip of the machine attached with the network switch port from the switch console

can i check the ip of the machine attached with the network switch port from the switch console? I just wanted to get the IP address of all the attached devices by running a simple command in switch ...
2
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2answers
1k views

How do I enable port security on Cisco switch?

I have a Cisco switch model 3500 series 48 port. I need to enable port security on this switch. Could you tell me the configuration commands to apply this policy?
2
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3answers
3k views

HP ProCurve 2524 - CLI Command to find Fiber Transceiver's Serial Number

Is there any cli command allowing to check the serial numbers of the inserted mini-GBIC modules on a HP J4813A ProCurve Switch 2524? The show interfaces transceiver [PORT-NUMBER] command which works ...
2
votes
1answer
118 views

In RSTP, where all switches generate their own BPDUs, are they limited to forwarding them only on designated ports? (like in classic STP)

I recently learnt a rule in STP: only Designated ports forward BPDUs. However, I'm not sure about this in RSTP since ALL switches generate their own BPDUs every few seconds. So, in a certain LAN ...
2
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1answer
61 views

What are network port maps and what are they used for by the networking team in an organization?

I am curious to know what information generally the port maps contain.
2
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2answers
81 views

Obtaining packet switch-port information via a mirrored port?

When sampling a mirrored port of a switch, is there any means of determining the switch-port information of the packet? Since Ethernet packets do not contain this information, I assume the answer is ...
2
votes
1answer
805 views

When are Native VLANs used? Are there times when a Native VLAN will never be used?

This is probably a simple one, but I am very new to VLANs. I'd like to avoid using VLAN 1 as well as gain a better understanding of when native VLANs come into play when setting up a switch. On ...
2
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1answer
918 views

Switch Port Configuration

I need to simply configure switch ports which are similar: switchport mode access switchport access vlan XX switchport voice vlan YY spanning-tree mode portfast I'm asking about using Smartports ...
2
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1answer
46 views

Does the dot3StatsInternalMacReceiveErrors counter include Vlan mismatches

I am wondering if the dot3StatsInternalMacReceiveErrors counter includes VLAN mismatches, i.e. Discards due to VLAN mismatch. http://oid-info.com/get/1.3.6.1.2.1.10.7.2.1.16 only explicitly lists ...
2
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1answer
32 views

When the data pass the Switch in port can represent cost value?

The snapshot is a tutorial of Switch. You see the bellow snapshot, from the ROOT SW1 node to SW3, there are two path: the author says the the path1(left side path) cost is 0 + SW3-in-port. the path2(...
2
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1answer
266 views

Broadcasting in L2 Switch

Hey guys, This is a Noob question. When a broadcast frame is received on a switch from a specific port, will it be automatically destined to all the ports in a switch ? ---------- (or) ---------- ...
2
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1answer
394 views

Switchport negotiation between trunk and dynamic desirable

If two switches are connected, one with switchport mode trunk and the other with switchport mode dynamic desirable, will both switches form an operational trunk?
2
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1answer
80 views

Auto smart ports macros triggers

My question is simple: I have a Catalyst 3560-X series switch and the below macro applied when i connect my laptop to the switch and it's working fine . function My_laptop_func() { if [[ $LINKUP == ...
1
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2answers
417 views

How does a switchport learn a MAC address

I have a very basic question. How does a switch port learn a MAC address? In this scenario say a host is not trying to communicate with any one. It is just plugged in the switch port. Does the host ...
1
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1answer
3k views

Why STP has to be disable on Trunk Ports?

I have 5 Switches on a Private Network 10.0.0.0/8 with 8 Vlans. On Access ports is running Rapid STP. On Trunk Ports between Switches should i disable STP or not? I would be very pleased if someone ...
1
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1answer
63 views

How can I config multi switch port efficiently?

I have a Cisco 2960-24TT Switch, no I want to shutdown all the switch port, I have to enter the interface then execute no shutdown and exit it then re-do this steps. how can I config multi switch port ...
1
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2answers
120 views

Do X.25/Frame Relay/ATM/MPLS have their own switches?

In the context of networking when we say "switch" we always think of Ethernet switch. But do we have X.25 switch, Frame Relay switch, ATM switch, and MPLS switch? If yes, how are they ...
1
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2answers
91 views

ping in the same VLAN with multiple switches in between

Refreshing VLAN knowledge with PT7.3, I came across some unexpected behavior. Why does a chain of switches having proper trunk configuration between them DROP packets? Trying to ping hosts from the ...
1
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1answer
143 views

L3 routing between switches with some VLAN's trunked

During a migration various L2 equipment will be replaced with all Cisco L3 switches and over time traffic migrated to routed subnets instead of trunked. There are two straightforward approaches that ...
1
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1answer
906 views

Cisco, No dot1q tunnel mode on switchport

The problem is: I can not find a QinQ(a.k.a. double vlan tagging or dot1q tunnel) feature in the following cisco switch: WS-C4510R+E, SUP8-E with WS-X4748-UPOE+E line card installed. The Cisco ...
1
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1answer
40 views

Can use virtual port as the port mirroring's destination port?

Port mirroring can mirror several source port to a destination port(mirroring port). I have several questions about port mirroring. in the dest port, how to differentiate the different source port? ...
1
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1answer
88 views

dhcp client not receving the ip address using two switches

1) In Router 4(R4) i have configured the 2 dhcp pool. first dhcp pool with ip address 150.10.10.0/24 and second one with 150.20.10.1/24 in subinterfaces f0/0.1 and f0/0.2 and encapsulated using (R4(...
1
vote
1answer
779 views

Cannot ping or SSH into new Catalyst 2960-CX switch from the server VLAN (1)

I recently setup a Cisco Catalyst 2960-CX switch at work (I'm a SysAdmin at a SMB). Our workstations use VLAN 3, but our servers use VLAN 1. The management IP of the new switch (in VLAN 3) is 192.168....
1
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3answers
4k views

Connecting two switches with an access mode port

I manage a switch, and I saw that on one interface there were 19 different MAC addresses, all of them on the same VLAN, so I guessed that there was a switch connected to that interface. Since all MAC ...
1
vote
1answer
2k views

Why HP comware shows "ARP limit exceded"?

%Apr 30 11:32:06:216 2000 ICT ARP/4/RATELIMIT: The ARP packet rate(178pps) exceeded the rate limit(50pps) on interface GigabitEthernet1/0/24 in the last 60 seconds. %Apr 30 11:33:06:824 2000 ICT ARP/4/...
1
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2answers
1k views

Single out switchports with multiple MAC addreses

Finding out how many devices are connected to a single switchport is easy on a non-stacked Cisco network switch with a sh mac add ta or sh mac add int fa/gi/eth. In our enterprise we have many large ...
1
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2answers
154 views

Locating device with IP address

I have a list of old IP addresses of devices, they need to be switched to a new IP scheme. At each switch in the company there patch panels that patch to the switch. The patch panel is labeled with ...
1
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1answer
31 views

ARP isn't showing all the interfaces/MAC bindings

I'm playing with Dot1x port authentication, the interface G2/0/2 is connected to a PC and is authenticated/authorized successfully: SW1-2960#show authentication sessions int g2/0/2 det ...
1
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1answer
100 views

What requirements must general firewall/routing software meet, to make OSI 2 port mirroring work correctly?

The basics are obvious, but there are technical points of networking implication which I don't understand. Some of these are general to networking, others general to all routing/firewall softwares ...
1
vote
1answer
836 views

Configure VLAN on Cisco SG-200 switch connected to a Meraki switch/network

I have a Cisco SG-200-26 switch connected to a port on a Meraki switch. The Meraki switch shows a list of all devices detected on that switch port (the Cisco switch and all of the devices connected ...
1
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2answers
79 views

Utilization of ports on switch

I have two WS-C3560E-48PD switches in the same organisation. How can I know which ports are utilized on the switches, and PC, phones, and printers? Is there are some command used to know above issue?
1
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1answer
1k views

Cisco switch not showing MAC flapping messages

I have two Cisco switches in the same VLAN, physically connected to each other. One of the switches is a 3650, and the other is a 4948. On the 3650, I can see MAC flapping messages between 2 ports, ...
1
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1answer
22 views

IPFIX vlanId element in access switchports

According to IANA definition, IPFIX elementId 58 vlanId is: Virtual LAN identifier associated with ingress interface. For dot1q vlans, see 243 dot1qVlanId. But according to RFC5102: Description: ...
1
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1answer
65 views

VLAN not working in ComNet switch [closed]

I'm trying to configure VLANs with 3 switches ComNet (2- CNGE2FE8MSPOE + 1- CWGE26FX2TX24MSPOE) and it's not working as I expect. It's the first time that I work with VLAN and I don't know If I didn'...
0
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3answers
159 views

Switch syntax, vlanXX and vlan [space] XX

How does a switch OS know that this is the same syntax? There are certain commands where you might reference the vlan like so "switchport access vlan 35", (a space between vlan and the number) and ...