Questions tagged [interface]

For questions about a physical or virtual interface on a network device. For instance: Interface configurations, troubleshooting and security.

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A question about WRED in QoS

I understand what WRED is and what goals it aims to achieve during congestion (drop packets, avoid Taildrop and so on). However, the actual principle of it is quite confusing to me. Consider this ...
Mitrixsen's user avatar
  • 803
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2 answers
71 views

Interface is down/down but internet works

I am managing a network at my company. A patch panel provides connections to the switch, which is connected to the router. One of the connections on the switch does not display a blinking green light. ...
Jossie Calderon's user avatar
1 vote
1 answer
75 views

Troubleshooting network issues; General inquiry

I work as a junior network admin at an ISP and I would like your help in resolving an issue whose cause is not readily apparent. Rn I am trying to troubleshoot a case where a switch interface randomly ...
Giorgos Amoiridis's user avatar
0 votes
1 answer
323 views

Why Linux answers ARP requests for IPs that belong to different network interfaces? [closed]

My machine has a physical network interface (eno1) and a bunch of virtual network interfaces (e.g. tap0). Each interface has its own IP and their subnets do not overlap. I noticed that if I perform an ...
felipeek's user avatar
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1 answer
355 views

Best Practices for Configuring Port Security on a Layer 2 Switch

How to configure port security on trunk and interfaces I'm learning about port security and have a few questions. I have a layer 2 switch with interfaces f0/1-22 in access mode to access VLANs, ...
Gekko's user avatar
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1 answer
210 views

How To Get Text Wrapped Around In A Note Box In Cisco Packet Tracer?

I am new to Packet Tracer, and I am trying to refresh my CCNA knowledge. I downloaded and installed PT version 8.2.1 which is the latest version by today (04/23/2023). I have been using it for a while ...
Shadi's user avatar
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42 views

What is "n6" in transparent architecture (NG-RAN)?

Hello everyone! I study the NG-RAN logical architecture described in TS 38.401, baseline for NTN scenarios. I have found the picture of transparent architecture, you see below. I can not find a ...
Anna Koroleva's user avatar
1 vote
2 answers
144 views

What issues can rise from web gui config changes then making other changes from the CLI?

I'm using a 9200L Cisco switch If I make changes in the CLI, then I make changes in the Web interface and vice versa. Will there be issues down the road with the config file getting corrupt or ...
13months's user avatar
  • 131
2 votes
1 answer
407 views

Confusion between MDI and MII

Media Dependent Interface Media Independent Interface My understanding is 2. is an interface between PHY chip and MAC block on the board. PHY chip can be on the board, or detachable. It is rather PHY ...
Taro's user avatar
  • 125
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10 views

How do devices on a network communicate when they are only connected through a router? [duplicate]

This is in my router's routing table: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.1.0 0.0.0.0 255.255.255.0 U 0 ...
imnglwhatheheckw's user avatar
1 vote
1 answer
401 views

Why specify the address of the default gateway in the routing table?

I’m struggling to understand the need of specifying the default gateway in the host’s routing table. When a host is building a frame to be sent, it needs to specify two MAC addresses; one for the ...
Mehdi Charife's user avatar
1 vote
1 answer
83 views

Does the host need to access the routing table to know if the destination IP address exists in the same network?

It is said that, in the process of building a frame, the host checks if the destination IP address exists in the same network. My question is concerning how the host performs this check. Does the host ...
Mehdi Charife's user avatar
0 votes
2 answers
88 views

Where does a host save its IP address?

While building a particular packet to be sent across or outside the network, the host, at a certain point, needs to specify the MAC address of the interface through which the packet is going to be ...
Mehdi Charife's user avatar
0 votes
1 answer
168 views

Huawei S5700, forwarding incoming untagged packets to bridge-domain (Error: The port has added to VLAN 1)

Trying to forward incoming untagged packets from an AC port to a bridge-domain. I'm following these guides: https://support.huawei.com/enterprise/en/doc/EDOC1100086966 https://support.huawei.com/hedex/...
GooGoo's user avatar
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1 answer
134 views

What’s the difference between Intel XXVDA2 and XXVAM2? [closed]

I have been looking at 25GBit NICs for SFP28 transceivers and came across the Intel XXV710 cards. Since I couldn’t figure out the naming scheme of these NICs, I have no idea what the difference is ...
comfreak's user avatar
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1 answer
1k views

Command for interface uptime

Is there any command to find out how long a particular interface has been up on a cisco switch ?
dlareg28's user avatar
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1 answer
869 views

VLAN routing on the same subnet

Consider following situation: You have 10.3.0.0/16 network without any VLANs. Now You want to divide it... You want Your IT department be able to reach the entire network, but sales department only ...
v.doro2's user avatar
4 votes
1 answer
422 views

Copying IOS from TFTP problem

I have a Cisco 4503 switch that had its IOS completely wiped. I have managed to boot from TFTP. the instructions I have tell me to switch the ethernet cable from the management port to a standard 10/...
Dan Cauley's user avatar
0 votes
2 answers
512 views

Question about subinterface DHCP relay CISCO

I want to make 4 PC got DHCP IP address No problem with left side, but right side 2 PC can't get IP automaitic. I think the problem is DHCP Relay. How can I use ip helper-address for subinterface of ...
Ordinary Sail's user avatar
1 vote
2 answers
153 views

What's the different between a "mask" in route table and interface?

if we took Windows as an example, we can use the command "netstat -rn" to show route table as follows: IPv4 Route Table ===================================================================...
柯鴻儀's user avatar
  • 113
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1 answer
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Unable to disable CRC check on Cisco 2960-X

I have a 48 port Cisco 2960-X running IOS Version 15.0(2)EX5. I'm trying to connect it to a Ubiquiti EdgeRouter4 using a Ubiquiti DAC Twinax cable.. I'm aware that this is technically not recommended, ...
robertmain's user avatar
2 votes
2 answers
333 views

Unable to add an abbreviated IPv6 to a Cisco router

I am very new to networking and playing around with GNS3. I am trying to configure a router to have 2 IPv6 addresses in a single interface (as far as I understood, this is possible with IPv6) I ...
Dasph's user avatar
  • 135
0 votes
2 answers
865 views

Is It possible to make Router On A Stick with two physical interfaces in the router?

If we try to implement router on a stick (ROAS) for try interVLAN communication, we must to use one Phisical interfase and split it into several "logicals" interfaces. Until Now all right. ...
NIN's user avatar
  • 105
0 votes
2 answers
1k views

can LAN port have multiple IP addresses of same subnet mask or different subnet mask

Can the router's ethernet interface have multiple IP's of the same subnet or different subnet mask? If yes what's the use?
Rohit's user avatar
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1 vote
2 answers
2k views

What does network interface do? and what's difference between a network interface and a network interface card (NIC)?

I'm a little confused about the network interface. Based on my understanding, a network interface does the translation between link-layer and internet layer, and does the ARP. Is that right? Also what'...
仲殷旻's user avatar
0 votes
2 answers
513 views

Adding Second Interface with Different Public IP for Same Internet Connection

We have a situation that I'm not sure how to proceed correctly. This location is currently utilizing two different firewalls - a Sophos XG 310 and a Sonicwall NSA 3500. The way this was originally ...
me55enger's user avatar
1 vote
2 answers
101 views

Basic conceptual questions about network interfaces

I have some basic questions as I am trying to understand the concept of network interfaces a bit better. Is network interface same as network interface card (NIC)? If not, what's the difference. What ...
user855's user avatar
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1 answer
93 views

issue regarding broadcast mac address

I read a line saying {Routes do not forward packets coming from one interface having broadcast mac address (FF:FF:FF:FF:FF:FF)} what is meant by one interface in that line? if router cannot broadcast ...
Rohit's user avatar
  • 31
0 votes
1 answer
2k views

Understanding the Burst Size against policer for 1G/10G interfaces in Juniper MX

We are facing one confusion with regards to burst size value against rate limit or policer in Juniper MX. Need to understand two things :- (1) Is the burst size limit defined in firewall policer ...
Nabeel's user avatar
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2 votes
0 answers
1k views

10G Interface on Juniper MX Stops Transmitting Output Optical Power

We have been facing an issue on Juniper MX series router. We have 10G interface on our router. Its does not matter whether interface is connected to DWDM or interface itself is a dark fiber. The end ...
Nabeel's user avatar
  • 1,120
3 votes
2 answers
253 views

What is the relation between software and hardware ports?

A port number is a 16-bit unsigned integer, thus ranging from 0 to 65535 https://en.wikipedia.org/wiki/Port_(computer_networking) And I think computers have small number of hardware interfaces(ports) ...
Henok Tesfaye's user avatar
0 votes
1 answer
491 views

Accessing an interface range that spans beyond one stack on a Cisco Switch

I want to configure Interfaces 0/3, 1/2 and 1/3 for example. Using interface range gig 0/3-1/3 did not work, is it simply not possible or is there a different syntax? EDIT: Of course aside using ...
Flying Thunder's user avatar
0 votes
1 answer
64 views

Routers FastEthernet interface clock autonegotiation protocol

In routers, for serial interfaces, we need to manually set the clock at the DCE router so that the ends of the connection can communicate. I know that in this way we are using time-division ...
m0ss's user avatar
  • 103
0 votes
2 answers
160 views

I still can't understand how routers work

I've seen a topology that has 1 router for each network, for example: Network1: 192.168.1.0 192.168.1.2/24 PC1 -> 192.168.1.3/24 PC2 -> 192.168.1.5/24 SWITCH -> 192.168.1.1/24 ROUTER 192.168....
Muath's user avatar
  • 7
1 vote
1 answer
697 views

VLAN Subinterface Removal - CISCO ASA

The below are the configuration of the subinterfaces in Cisco ASA firewall and currently sub-interface 0/1.1 is only passing traffic and I need to remove 0/1.2 configuration from here as it is unused. ...
Labrathor's user avatar
0 votes
1 answer
1k views

Multiple mac adrress on one cisco switch interface

How can i config Multiple mac address on one cisco switch interface? (I have 3 laptops and i connect only one laptop every time(I switch between them), and i want to config only one interface with the ...
Jasmine's user avatar
0 votes
1 answer
7k views

JunOS: FPC Major error alarm

I hope everyone is doing fine! This morning I've run into a problem. My uplink interface went down for unknown reasons. Upon checking system alarms I see this: show system alarms 1 alarms currently ...
Nenq's user avatar
  • 45
1 vote
2 answers
66 views

Steps on troubleshooting a network

If I have to troubleshoot a network stating that one of the interface is not working (i.e, a link is down), what steps would I need to take to make it working again?
Utsav's user avatar
  • 127
0 votes
2 answers
2k views

Fiber dBm transceiver power level at warning

We have cisco nexus 9000 and one of 40G interface showing port transceiver power level at warning when i check on command line i found following. Question: what is the normal power level for ...
Satish's user avatar
  • 4,369
1 vote
0 answers
33 views

Change name interface [closed]

Sorry for my English.... I want to change the interface name, what I don't know sure the steps.... First I should know my interface name and mac from it, ip a Seconds, down my NetworkManager, ...
biotza's user avatar
  • 11
2 votes
1 answer
3k views

Link Aggregation from Cisco to Palo Alto using 10 gig interfaces, port on Cisco shows "waiting to be aggregated"

I am trying to bundle two 10-Gig interfaces on PA-3020 to Cisco Cat9300. Previously, I had bundled two Gigabit interfaces on same devices and everything worked fine. But now, when I try to configure ...
Ankit Badani's user avatar
0 votes
2 answers
34 views

Cisio interface naming rule

I'm very new to networking. I noticed in GNS3 lab environment, if I want to configure IP address for an interface of a router, I can use int f0/0 or int fastEthernet 0/0. What's the naming rule here? ...
Just a learner's user avatar
2 votes
2 answers
725 views

Relationship between full duplex and speed

Full-duplex data transmission means that data can be transmitted in both directions on a signal carrier at the same time. but my question is if we have an interface with 100Mb speed and full-duplex ...
guidev's user avatar
  • 563
0 votes
1 answer
173 views

Bandwidth limit between CPE and Provider Equipment

I have 4 different WAN links for redundancy one of them is 15mbps MPLS and the other ones are 30mbps Internet , 50 mbps Internet and 10 mbps MPLS , the way that it is set up is that we have load ...
Kejimire's user avatar
0 votes
1 answer
56 views

Can't access services on my other IP on same network interface GNS3 and Host [duplicate]

I have one physical NIC that is assigned an IP address (10.14.255.240). Inside of GNS3 network simulation tool, I also have a another 'virtual' interface with another ip address (10.14.255.245). Both ...
nametable's user avatar
1 vote
1 answer
1k views

Why a NIC in promiscuous mode and not will impact the capture packages?

I have a question about network interface Promiscuous mode, A NIC in promiscuous mode can receive all data passing through it regardless of whether the destination address of the data is it. If the ...
aircraft's user avatar
  • 1,128
0 votes
0 answers
117 views

Brocade XMR randomly losing virtual interface IP address

We have a pair of XMR routers configured 100+ VLANs running VSRP downstream and BGP upstream. At random times, the IP information is deleted and I have to go in and reset it. Each VLAN config looks ...
user3280964's user avatar
6 votes
1 answer
396 views

How to use an optical tap? Which fiber should I use?

We have an optical tap (https://www.fs.com/products/73675.html) that provides an LC connector providing two TX instead of RX/TX. As you can see, there is a conflict. What I think I need: A splitter ...
Alexis's user avatar
  • 396
0 votes
1 answer
142 views

Static IP assignment 3750X - DHCP Override

I have a 3750X that I am running some testing with. I have a VLAN interface that is using 10.10.10.254/21 as it's primary IP and 192.168.10.254/24 as it's secondary IP. See below: interface Vlan10 ...
Craken's user avatar
  • 681
3 votes
1 answer
137 views

Switching interface VLAN ID Mid-Production

I was wondering if there was a way to switch out the VLAN ID from VLAN1 to VLAN10 without impacting the connectivity of the end users? Can I simply copy and paste from one interface VLAN to another? ...
Craken's user avatar
  • 681