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Questions tagged [trunk]

For questions about trunks, layer-2 links across which traffic for multiple VLANs travel.

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Configuring VLAN Trunk on JunOS

I have a Juniper EX-4300-48P and I was trying to test out connecting it to a TP-LINK TL-SG108E and the intended network flow is as follows: EX-4300-48P Interface ge-0/0/0 set to trunk VLAN 121,125,126 ...
user24681711's user avatar
1 vote
1 answer
134 views

SOLVED - Quanta LB6M Trunk and Vlan

I have 2 Quanta LB6M and a Juniper EX4200 and need to create vlan and trunk For vlan interface i have this: interface 0/27 vlan pvid 31 vlan participation exclude 1 vlan participation include 31 exit ...
Ertu Kocak's user avatar
0 votes
1 answer
102 views

Non VLAN Tagged Traffic Not Going Through Trunk Between Cisco Switches

Good day all. I am running through a packet tracer exercise and am stuck on where to go next. Forgive me if I am missing something obvious, I have not touched any cisco networking or networking in ...
cnrdvdsmt's user avatar
0 votes
1 answer
76 views

Switch Configuration - Change the trunk allow VLAN

May i know any service interruption if i issue the command on changing the trunk allowed vlan on both end: switchport trunk allowed vlan 10, 20, 30 to switchport trunk allow vlan 10, 20, 30, 40
KKNg's user avatar
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1 vote
1 answer
201 views

Why its need to use trunking when using etherchannel? [duplicate]

what's the reason to use trunking by using the 2 below commands: switchport trunk encap dot1q change the mode to trunk between EtherChannel ports the second question why to make native vlan under ...
banoosh's user avatar
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0 answers
297 views

Cannot tag an interface for a specific VLAN : % Error: Tagged flag mis-match Te 0/3

I trying to tag an interface for a specific VLAN on a Dell S4810 : S4810#show run int ten 0/3 ! interface TenGigabitEthernet 0/3 no ip address mtu 12000 switchport flowcontrol rx on tx on no ...
SebMa's user avatar
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1 answer
50 views

what is the relation between DTP and VTP?

the ideas behind VTP & DTP are different, then why do we need to make sure that the VTP domain on both sides is the same otherwise the DTP will not work?
banoosh's user avatar
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1 vote
0 answers
180 views

Can't Pass 1 VLAN Through Trunk

I have 2 Cisco switches running IOS with VLANS 20,30,40,50. On SWITCH1 I have servers on Ports 1,2&3 on VLAN 30. I also have a laptop on port 5 on the same VLAN 30 and can ping the servers. They ...
JukEboX's user avatar
  • 461
0 votes
1 answer
223 views

No Ping Through Cisco Trunks

I am trying to ping on my management VLAN across a trunk between 2 Cisco switches. Both switches have the following configs interface TenGigabitEthernt1/1/1 switchport trunk native vlan 5 switchport ...
JukEboX's user avatar
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4 answers
2k views

Communication between different VLANs

In my previous understanding, there is no way to communicate between two VLANs using only layer 2. After all, this is the purpose of having VLAN. I found a forum that claims the following. 1.VLANs can ...
jacky chong's user avatar
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0 answers
828 views

Nexus 7706 - switchport trunk allowed vlan not working - all VLANs are being allowed

I noticed that my two Nexus 7706 do not limit the trunk VLANs to what switchport trunk allowed vlan is set to. Sample configuration: interface Ethernet1/15 switchport switchport mode trunk ...
Cha0s's user avatar
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2 votes
1 answer
623 views

How do you drop (or ignore or filter) all untagged traffic on an 802.1q trunk port?

This answer says "[a] trunk has optionally one untagged VLAN and many tagged VLANS." I always thought specifying switchport mode trunk would drop untagged frames at that port, but that ...
KJ7LNW's user avatar
  • 167
0 votes
3 answers
462 views

What does `switchport trunk native <n>` do when in `switchport mode trunk`?

According to this article Cisco recommends VLAN 99 for the "native VLAN". But what is the point when operating under switchport mode trunk? Doesn't switchport mode trunk filter all tagged ...
KJ7LNW's user avatar
  • 167
-1 votes
1 answer
77 views

aggregating Cisco 2960 ports with Cisco 3850

I'm new to networking. I have two switches: Cisco 2960 & Cisco 3850. I want to connect 4 Trunk ports of these switches to each other. Since Cisco 2960 port speed is 1G and Cisco 3850 is 10G, I ...
free's user avatar
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1 vote
1 answer
563 views

VLAN trunking - how to ping PC4 from PC1?

I'm still a beginner with VLANs and trunking, and I'm trying to get this topology working. Specifically, I am unable to ping PC4 (10.0.10.11/32) from PC1 (10.0.10.10/32), despite both of them being on ...
Deepak's user avatar
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1 answer
64 views

How Switchport Trunk work?

I the scenario below; I can sniff the traffic between Win7 and UbuntuSrvr on Line A but this is cannot be done on Line B Note: ports are on trunk mode. Why this is happening??
Mehran's user avatar
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2 votes
1 answer
55 views

Access and Trunk Port [duplicate]

I have an access port that I'm trying to change to a trunk port. So, while I'm on the interface I want to change and do: switchport mode trunk switchport trunk allowed vlan x a show run command then ...
Bob's user avatar
  • 123
1 vote
1 answer
1k views

Need help with HPE tagging and hybrid-mode port

At my office I have two switches. SW-1 (HP-V1910-48G) is the switch my desktops are connected to, and SW-2 (HPE-1920 JG927A) is where my server rack with my dhcp and default gateway is connected. ...
Grosser Kurfurst's user avatar
1 vote
1 answer
73 views

Access layer switches uplink mode

We have core, distribution and access layer switches. the switches in access layer connect several workstations on VLAN 20 only. we have DHCP server on VLAN 1 but is on another switch with all servers....
mdnfiras's user avatar
  • 113
2 votes
1 answer
505 views

Why I can't ping my switch Vlan99?

In the following network, I have configured every device but somehow I can't ping my Customer-PC and Technical-PC to PasirGudang-SW and Segamat-SW. The PCs can ping the other ip address just fine ...
Tyah Alwi's user avatar
0 votes
1 answer
230 views

Do unicast frames get sent to all switches associated with the target VLAN?

If a network topology has a VLAN which spans multiple switches, what happens if a frame is sent to a MAC address that is connected to the source device's "home" switch? By that I mean if a ...
CJ7's user avatar
  • 101
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0 answers
258 views

Dropping packets when mirroring a switch trunk port

I'm building a test lab to support a networking monitoring application I'm developing. I have written a simple UDP packet generator and receiver, and I use iperf3 to create some bulk background ...
Robert Olivier's user avatar
0 votes
1 answer
1k views

pfSense - Trunking VLANs on LAGG vs. individual links

We are a small business. I am running pfSense on a decommissioned developer's PC. We have also a Cisco SG 300 L3 switch, capable of VLANs and LAGG (link aggregation). I am going to do RoaS (router on ...
Pavel Tankov's user avatar
2 votes
2 answers
622 views

Connecting two HP 2910al Switches using SFP to get 2Gb/s speed

I would like to Connect my two HP 2910al switches using SFPs to get a maximum of 2G links. is this possible, and how? I want to make both of them to use the IP address (ex 192.168.2.xxx). I have the ...
Kikomi's user avatar
  • 27
0 votes
1 answer
977 views

Connecting two Stacked Aruba 2930M Switch with third one using LACP

In the skit, I would like to connect the two Stacked switches with a third one using the SFPs+ Modules and therefore I need to configure the LACP for them. How can I configure the LACP on both the ...
Kikomi's user avatar
  • 27
2 votes
1 answer
546 views

Port only in trunk mode vs encapsulating the frame

A network with 2 switches, each switch has 2 vlan, one called vlan 10 and another vlan 20. A port-channel with 2 uplinks (trunk). Why in a layer 2 scenario I don't need to configure the trunks with ...
Bruno Dias's user avatar
2 votes
2 answers
4k views

Can't add VLAN in the "allowed VLAN"

Why is this command not accepted? switchport trunk allowed vlan add 52,160,176,177,247 I tried adding only one VLAN; it's also not accepted. No error is shown or anything; it's just not showing when ...
BehindTheWall's user avatar
0 votes
2 answers
5k views

How to connect two different subnets

This may be a very basic question, but I'm a networking newbie. So I have the following setup: Server with one NIC on IP 192.168.10.1/24 (Network A). It is not possible to change this IP. Computer A ...
Tobias von Falkenhayn's user avatar
1 vote
1 answer
246 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'...
user3819641's user avatar
0 votes
2 answers
2k views

How to monitor vlan using SNMP?

I am a newbie to building a monitor system using Prometheus and SNMP exporter, I have succeeded get metric from the physical interface, but I want to monitor VLAN on a trunk port, is that possible ? ...
Jimmy Nguyen's user avatar
1 vote
2 answers
399 views

I cannot Encapsulate on Router

I have VLAN10 and VLAN20, I am trying to communicate between computers with the same VLAN on the following setup: I want to apply encapsulation from Router but it doesn't seem to recognize ...
Ufuk Keskin's user avatar
4 votes
1 answer
56k views

difference between switchport trunk encapsulation dot1q and switchport mode trunk

I am new to network engineering and I am currently delving deep into L2 functionality.what is the difference between these two commands: 1 switchport trunk encapsulation dot1q 2 switchport mode trunk ...
gene's user avatar
  • 43
0 votes
1 answer
596 views

Trunking multiple VLANs into a single trunk port on a 3650 Switch

Morning: I'm new to the world of Cisco Packet tracer, and I am creating a network for a uni project. So far, what I have is: 5 VLANs (subnetted to 192.168.2.0/26, 192.168.3.0/36 etc) All are ...
LordVader's user avatar
0 votes
1 answer
1k views

Why some situations, PC can connected to trunk port and work fine?

I want to know about tagged and untagged vlan mechanism then I try to configure like this When I connected PC3 to trunk port on Packet Tracer, It doesn't work and a switch dropped PC3's frame if I ...
Jarunchairat Wosonthia's user avatar
0 votes
2 answers
222 views

If we already have default VLAN, Why we need Native VLAN? [duplicate]

What is the need of Native VLAN and default VLAN. How they are related? Can Somebody explain this in detail?
imsiddhant's user avatar
1 vote
2 answers
1k 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 ...
Daniel B's user avatar
  • 113
0 votes
3 answers
887 views

IOS. Whats the difference between these 2 commands

I am completing an online course for the network+ and am going through one of the labs. Here is a diagram of the network in question. Specifically I have a switch with 24 fast ethernet ports and ...
Teererai Marange's user avatar
0 votes
1 answer
1k views

Why can't I connect to PfSense via the switch?

Our current firwall is deprecated and we decided to exchange it with an PfSense server. In my test setup I configured the interfaces as follows: igb0 = WAN enabled igb1 = LAN (should be VLAN trunk ...
CodeNinja's user avatar
  • 219
0 votes
2 answers
378 views

VTP pruning used in combination with allowed vlan

I have a network on which most of the switches are running VTP client/server mode. Few switches are not yet in that mode - for specific customization or because they simply cannot handle it. Thinking ...
mouch's user avatar
  • 170
3 votes
1 answer
391 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 ...
AtomiX84's user avatar
  • 145
0 votes
2 answers
671 views

Cisco router on a stick with public ip wan (ISP)gateway

I am trying to create a router on a stick with an outside facing sub-interface with a public IP from an ISP. I have tried to configure NAT and routing but I just cant get to ping the internet. I'm ...
Kha Kali's user avatar
1 vote
1 answer
226 views

How to define trunk port between vmware esxi host 6.5 and switch? [closed]

I create some virtual machine in different vlan but i can not set trunk port from vmware to transfer vlan information.
Amir Sabeghi's user avatar
1 vote
1 answer
601 views

Removing VLANs from core trunks (.1q)....?

I am a little embarrassed I do not know the answer to this already, well I think I know the answer but I am not 100% sure and this I need to be 100% sure on. We have several core .1q trunks that we ...
Pravius's user avatar
  • 13
6 votes
2 answers
3k views

Can a single subnet work across several switches?

New to networking and studying hard but limited access to a kit to try things at the moment... My question is - if I had, for example, two Layer-2 switches cable connected, could I have devices on ...
ICSOTSecurityEngineer's user avatar
0 votes
1 answer
160 views

Routing between 2 VLANs with one HP Switch

I need help with VLAN: I have a WiFi AP with the IP 192.168.100.190. There are 2 SSIDs with VLAN 1 and 2 created. As a router I have a Sophos UTM with the IP 192.168.100.199. Furthermore, I have an ...
LuckyExchange's user avatar
0 votes
1 answer
151 views

Why Access ports should have the same trunk native vlan? [closed]

In the current switch Management VLAN is 48. Can you please someone explain it to me, why we dont give trunk native VLAN as 48, and we configure the same as access VLAN? Thanks in advance.
Jim Pap's user avatar
  • 419
1 vote
1 answer
8k 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 ...
Jim Pap's user avatar
  • 419
0 votes
4 answers
213 views

Confused in using the ports for trunking mode

The ports are as follows: for the switch on the left side the upper port is fa0/1, below it is fa 1/1 and below fa1/1 is fa2/1. For the switch in the middle the left port is fa0/1 and the right port ...
Muhammad Ahmad's user avatar
4 votes
1 answer
2k 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 ...
Craken's user avatar
  • 681
4 votes
1 answer
8k views

spanning-tree port type edge trunk on port-channel vs physical interface

If i configure spanning-tree port type edge trunk on physical interface instead of port-channel does that work? Or i have to do spanning-tree port type edge trunk on port-channel ? Example: ...
Satish's user avatar
  • 4,379