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Questions tagged [switch]

For questions about network switches, the term commonly refers to a multi-port network bridge that processes and routes data at the data link layer (layer 2) of the OSI model.

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Why is routing not working on my Dell N2048 switch

I am in the process of replacing some older Dell Powerconnect switches with a some Dell N2048 switches. While doing this I wanted to go ahead and segregate certain areas of my network using VLANs. ...
Michael Haynes's user avatar
6 votes
0 answers
741 views

Cisco nexus 9396 rebooted with reason xbar_client

Today my one of cisco nexus 9396PX switch got rebooted and this is what i found, based on following logs what could be wrong? We don't have Cisco support for this switch, trying to see if i can get ...
Satish's user avatar
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5 votes
0 answers
1k views

Cisco nexus STP loopguard

I have cisco nexus switches in vPC and they are connected to HP c7000 blade center switches and all my c7000 blade server has Linux Bridge is running, i believe something went wrong somewhere in Linux ...
Satish's user avatar
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4 votes
0 answers
189 views

Why does RSTP send proposal bit and agreement bit as '1' initially?

From a recent Wireshark capture of a RSTP BPDU on a switch, both proposal and agreement bits were set to '1'. In my understanding, initially both switches 'propose' themselves as root. The better root ...
noobmaster69's user avatar
4 votes
0 answers
475 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 ...
Martin Ledermann's user avatar
3 votes
2 answers
318 views

Colocation Rack Networking

I'm a sysadmin tasked with finding a managed service provider or networking contractor to build out our new colo space networking. I'm hoping to get some input to make sure I don't sound like an idiot ...
jawsadmin's user avatar
2 votes
1 answer
160 views

6125XLG blade switch IRF configuration in c7000 chassis

I have HPE c7000 chassis with 612XLG switches. I am trying to setup IRF between blades switches. somehow i am not able to bring up irf-port interface. In 6125XGL TE1/0/17-20 ports are internal ...
Satish's user avatar
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2 votes
0 answers
723 views

Cisco nexus spanning-tree logging to syslog

I am trying to send my spanning-tree events to remote syslog but somehow it doesn't work, This is what i have in my config. N3K# sh run | grep logg logging level spanning-tree 7 logging server 172.29....
Satish's user avatar
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2 votes
1 answer
125 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 == ...
Walid Slaaouiter's user avatar
2 votes
1 answer
353 views

Allow outgoing connections

I have an Arista switch (EOS) and I'm having trouble allowing outgoing connection from the switch to the outside. Using tcpdump I can see that no packets are being allowed. This has an impact on DNS ...
user avatar
1 vote
1 answer
69 views

should I go multiple switch or one big switch

So I have a 2.5Gbps NIC on my server PC, but my main questions are: note: I'm using consumer grade switches will a 2.5Gbps switch split the load with two 1 Gbps switch? will the 1Gbps be better on ...
randomaire's user avatar
1 vote
1 answer
54 views

Lot of packet retransmission with bonding (802.3ad) on switch between two servers

I am currently working on setting up a 2 node-storages network with Mellanox 2x 10Gbit cards, connected through one mikrotik switch CRS326-24S+2Q+RM. I have configured bonding in mode 802.3ad with ...
enp4s0f0np0's user avatar
1 vote
1 answer
74 views

If a cisco switch is on the other side of a wire when it's plugged into a cable tester; is that dangerous?

This cable tester has numbered fobs that plug in the other end of an Ethernet port and report back which number they are; If the cable tester is accidentally plugged into a switch port when the test ...
leeand00's user avatar
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1 vote
1 answer
434 views

How FDB (Filtering Database) is filled out

I would like to understand what is used as a VLAN column in the FDB. For ACCESS port it is PVID if frame untagged or frame VID if frame is tagged, for TRUNK it is allowed VLANs? We can represent the ...
Manticore's user avatar
  • 141
1 vote
1 answer
6k views

J9450A HP 1810-24G Switch firmware upgrade

I'm trying to upgrade the firmware on my J9450A HP 1810-24G Switch, which presently has firmware P.1.6, eCos-2.0 The firmware-update-for-an-1810 question is out there on the internet, but the ...
rih5342's user avatar
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1 vote
0 answers
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What are non-learning and learning VLANs?

I was going through some IEEE standards for switches (IEEE 802.1aq and IEEE 802.1Qca), and came upon a terminology of learning and non-learning VLANs. I read that learning VLANs are used in Shortest ...
noobmaster69's user avatar
1 vote
1 answer
536 views

How to block telnet access for one particular network from all networks except one using Extended ACL

Scenerio is given in the picture. I want to block all the networks except 192.168.5.128/25 from doing telnet of 192.168.5.0/25.
Umair's user avatar
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1 vote
0 answers
388 views

Untagged VLAN in EVPN+VxLAN

I am dealing with very strange issue but wanted to check with experts if i am doing anything stupid or not. I have small size EVPN+VxLAN clos network (OSFP+iBGP+Multicast+Arp-suppression (no ...
Satish's user avatar
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1 vote
0 answers
124 views

Using a switch to dynamically connect and disconnect multiple devices together in a point to point configuration

I have an interesting issue. I have to use a switch to dynamically connect and disconnect multiple devices together in a point to point configuration, without changing anything on the end user side. ...
Justin Lavan's user avatar
1 vote
0 answers
153 views

Connecting layer 3 switches together without trunking

I currently have 2x Juniper EX4200 and I'm looking into changing it into Ubiquiti EdgeSwitchs. The diagram: SW01 and SW02 are connected to each other using OSPF P2P. Both of the switches have their ...
amit177's user avatar
  • 36
1 vote
0 answers
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Why my ae interface Link type is down but the physical interface is up?

Why my ae interface Link type is down but the physical interface is up? In my convergence layer Switch, I use two Juniper EX4300 devices realize the Stack: so there have xe-0/0/x and xe-1/0/x ...
244boy's user avatar
  • 1,777
1 vote
0 answers
3k views

Cisco 2960X stacked switches pop up ACL error messages without any ACL configured nor input

I have a few Cisco 2960X with the fiber flexstack modules, when I boot them up, I always got these message: 'Duplicate sequence number. Failed to add ace to access-list' These are brand new switches ...
F.Y.Sun's user avatar
  • 11
1 vote
0 answers
384 views

How Cisco Line Protocol works

How do Cisco Line Protocol works ? I could read this: https://www.cisco.com/c/en/us/support/docs/content-networking/keepalives/118390-technote-keepalive-00.html, about Ethernet Interfaces keepalive ...
bdes31's user avatar
  • 1,085
1 vote
0 answers
272 views

Block internet on a Cisco catalyst 3560 port

Good day Is there a way to block a specific port in a Cisco Catalyst 3560 switch to block the user from accessing the internet but still have full access to the internal corporate resources. The ...
Andre Smit's user avatar
1 vote
0 answers
183 views

How to keep the VRRP failover mechanism?

referring to the diagram below, we have 2 VLAN's for voice, primary route for VLAN1 (red) is the left side, and VLAN2 (green) is the right. As it stands we have a nice easy setup, where VRRP kicks ...
user10021657's user avatar
1 vote
0 answers
1k views

Even ips pinging but odd ips not pinging

We have following network, and i have multiple host connected to TOR switches configured with public IPs. We have HSRP running on vPC switches. interface Vlan100 description *** Public VLAN *** ...
Satish's user avatar
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1 vote
0 answers
489 views

HP ProCurve 6120XG with Cisco configuration

ProCurve 6120XG Blade Switch with Cisco trunk I have c7000 HP blade Center with ProCurve 6120XG Blade Switch and i am creating trunk to my TOR1 Cisco switch (Nexus 3064), but having issue related VLAN ...
Satish's user avatar
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1 vote
0 answers
310 views

How does a Switch Fabric Module work internally?

I am interested how does a switch fabric module work internally. What interfaces does it use to physically connect the I/O modules on switches? Where are the CAM / MAC tables of the switch? Are ...
yoyo_fun's user avatar
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1 vote
0 answers
66 views

How does Fabric Connect protocol work?

What are the algorithms that are used by Fabric Connect protocol/protocols to choose the best path to forward a packet? I know that Fabric Connect is used to replace the Spanning Tree Protocol that ...
yoyo_fun's user avatar
  • 1,541
1 vote
0 answers
220 views

3com 5500G migration to force10 s4810

I am doing this migration with these 3com switches.So our client told me that the configuration was made for a network administrator who was fired some years ago. So I dont have any kind of ...
MarcoAlveiro's user avatar
1 vote
0 answers
470 views

Optimizing access control lists on a Cisco SG500X-48 Small Business switch

I am trying to optimize the access control list rules on a Cisco SG500X-48 Small Business switch (on Layer 3). The general aim is to regulate the traffic between two VLANs (e.g., 10 and 30) in such a ...
Kit's user avatar
  • 111
1 vote
0 answers
178 views

Wireless guest vlan issue

I am trying to separate the traffic of a wireless controller using VLANs. I have a Cisco 4400 wireless LAN controller configured to connect to the guest VLAN on an HP ProCurve 5412zl switch. The ...
halemaximus's user avatar
1 vote
0 answers
259 views

VLAN issue in HP 5406 switch after a power outage

Last week we had a power outage. When power came back, our HP switches came back online but with a problem. A few VLANs in our HP 5406 switches did not get an IP address from DHCP server, the other ...
Syed's user avatar
  • 11
1 vote
0 answers
858 views

Dell Switch N3048 with PowerConnect 6248

I have two Dell switches and its a classical VLAN Scenario that does not want to work. PowerConnect 6248 is connected to the outside world and from there i like to bring new subnet ( this is already ...
user3523605's user avatar
1 vote
0 answers
750 views

PowerConnect 2808 and syslog

I have a pair of Dell PowerConnect 2808 managed switches. I am attempting to enable syslog on them, but not having any luck. I have searched the web interface, used telnet to log into the CLI ...
Randal R.'s user avatar
1 vote
0 answers
3k views

Dual Internet connections in active/standby mode without BGP

hello everyone attached is my diagram in which i am facing problem as you can see i have two internet links from two ISPs in which i want failover between two ISPs without using BGP or NAT because i ...
Networker's user avatar
1 vote
1 answer
76 views

ws-c3750x-48pf-s v02 not booting after password reset procedure

I tried to do a Password Reset Procedure on ws-c3750x-48pf-s v02 - 48-Port PoE, but at the end of the procedure the switch no longer works after multiple restarts and pressing the mode key, I always ...
user83374's user avatar
0 votes
0 answers
32 views

Network scheme based on traceroute commands - is my thinking correct?

I want to create a hypothetical scheme of network containing the 3 routers (R1, R2 and R3) that were listed when running 2 separate traceroute commands. traceroute 1: 1 *** (...) 9 R1 (80.249....
thefool's user avatar
  • 101
0 votes
0 answers
71 views

Connect PC to HVAC Router

I have a network with multiple Cisco 9300 Switches and 9606 Core switches. We had a PC connected directly to a Carrier i-Vu XT Router. The PC needs to be moved to another building. I connected the ...
Rick151's user avatar
  • 21
0 votes
0 answers
53 views

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
0 votes
1 answer
58 views

Cisco nexus C93180YC-EX sflow configuration

I am running cisco nexus C93180YC-EX switch and I would like to enable sflow for collector. I did similar config on 9396PX model and it works but Nexus 93180 is little different. I am running NXOS 9.3....
Satish's user avatar
  • 4,379
0 votes
1 answer
624 views

Reset and Login Issues with C9500-48Y4C Switch

I have a Cisco C9500-48Y4C Switch, but I forgot the login credentials while configuring it, which has resulted in me being unable to access the Switch. Could you please guide me on how to reset this ...
berniecheniitt 's user avatar
0 votes
1 answer
43 views

What is the difference between these OIDs on a Aruba Wlan Controller?

For my bachelors thesis, I have to monitor the WLAN Access Points of the university campus. For example, number of connected Clients and how many Clients are connected to each Access Point. Therefore ...
Schmida's user avatar
0 votes
1 answer
95 views

Problems with twice-NAT on Cisco 3548

I'm trying to get Twice-NAT working on a Cisco 3548 switch. I have a VRF set up with 2 L3 ports on it - Eth1/33 has ip address 20.20.255.250/16 and is nat inside Eth1/34 has ip address 10.10.1.211/24 ...
Kevin's user avatar
  • 101
0 votes
0 answers
75 views

Is there a way to gather data of Optical Module Status and the CPU Utilization through SNMP protocol?

When using the snmpwalk command to query a Cisco SF302-08PP switch with the -c public community string, am not able to find data related to Optical Module Status and CPU Utilization. I am trying to ...
mema's user avatar
  • 11
0 votes
0 answers
76 views

End to end delay over N link including the (simplified) propagation delay

It is well know (see this question) and easily verifiable that end-to-end delay in case of trasmission of P packets of size L over N equal links (same transmission rate R) with zero propagation delay ...
frhack's user avatar
  • 101
0 votes
0 answers
62 views

noob learning cisco

I'm trying to teach myself how to use cisco devices. i was given an router, switch and firewall. so far i been able to set up vlan and have intra vlan routing working. My issue is having the switch ...
Stu Villanti's user avatar
0 votes
0 answers
35 views

Cisco switch ios update without change license

I need the following ios switches to be updated to the latest "license-free" version to fix vulnerabilities: C3560CX-12pd-S C3650-48PS-E C3850-12S-E C3850-24T-E C3850-12S I didn't find any ...
khatabakhshnadia's user avatar
0 votes
1 answer
329 views

dot1q L3 router sub-interfaces and L2 switch ports

I have a router with multiple L3 sub-interfaces. On the other side I have a L3 switch (Nexus 9K) that I'd like to have multiple hosts that are on the switch route their traffic to one of the router ...
Terry Grace's user avatar
0 votes
0 answers
406 views

Cisco nexus 9336-FX2 ETHPORT-5-IF_DOWN_LINK_FAILURE

I am seeing following error on 100G interface. (SFP bought from fs.com) nxos version 9.3.10 2023 Oct 11 00:41:12 spine-1 %ETHPORT-5-IF_DOWN_LINK_FAILURE: Interface Ethernet1/4 is down (Link failure) ...
Satish's user avatar
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