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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1answer
589 views

Urgent: how to configure different interface using same ip subnet in asa 5506?

Scenario is in old asa firewall 5505 I have switch port access vlan command in different interface. Just like below: interface Ethernet0/0 ! interface Ethernet0/1 switchport access vlan 2 ! ...
2
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2answers
2k views

Cisco 3560 interface counters, are the counters reset automatically?

I have a Cisco 3560G switch. Are the interface counters reset automatically, recalculated in a specific interval (5 minutes?), or not at all? I want to get (hourly, daily, monthly, etc) interface ...
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1answer
2k views

Why is my ACL not blocking traffic on my cisco router interface?

So here is my config. I want traffic coming from all networks except 172.23.1.0/24 to be blocked by inferface fa 0/0 So on the router I creater 2 ACLs ACL 10 R1# access-list 10 permit 172.23.1.0 0....
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1answer
574 views

What is the max throughput I should expect a Cisco 3560-PoE to have for a small network?

I have a Cisco 3560 48-PoE. I am trying to use it for imaging computers. I can make it work but I only get 1gb a minute. I have tried various tweaking but that's about has high as I can get. What ...
4
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1answer
1k views

limit bandwidth on a Cisco switch port,

Our company has a 3/.5 DSL connection. On this connection we have a VPN where the execs are able to access files on the network as well as VOIP. On this connection we also have our exchange email ...
1
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1answer
584 views

How “show inventory” displays SX SFP?

I've a Cisco 3925 and it's not quite clear why an "1000BASE-SX SFP" entry is visible in the inventory. Is it only visible when the SX SFP is in use? (I've no chance to modify it.) NAME: "CISCO3925-...
2
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2answers
835 views

Command for showing unused ports over time on Cisco switches

I was looking at a previous question about this where a command was given to look for all ports that had not been used in 6 weeks. I ran the command but it doesn't give the port names just the line ...
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1answer
44 views

How do i set this ACL on the router

I was told in a previous answer to use ip access-list extended TEST deny ip host <PC0 address> host <PC5 address> permit ip any any But, whats the command to set it on the router ...
1
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1answer
407 views

how to connect 2 routers to communicate?

What cable connects routers to communicate ? I am using Packet Tracer Simulator, and I connected 2 routers using a DTE connector. After doing this, I am unable to ping between the 2 routers. Is using ...
2
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2answers
7k views

what are input errors on the CISCO switch?

In my topology, I have connected spirent - traffic generator to MRV switch ( L1 switch) and then connected to CISCO switch. I am seeing some input errors on this interface. What does it mean? Does it ...
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2answers
276 views

Required VLAN overlapping allowed?

I configured the switch for two VLANs, as below: Projects-3560-(config)#int vlan11 Projects-3560-(config-if)#ip address 10.110.1.1 255.255.255.0 Projects-3560-(config)#int vlan10 Projects-3560-(...
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3answers
133 views

Gigabit NIC stuck on 100mbs

My main problem started when i installed 4 gigabit NIC into my computer. The 4 NIC are connected to GB linksys switches, each in different location,1 of the 4 gives GB and the others are stuck on 100 ...
2
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1answer
2k views

How exactly is “input rate” calculated in IOS “sh int” output?

Cisco IOS routers display input and output bps and pps values for load-interval time period in sh int output. For example here is load-interval set to 30 seconds: C1921#sh int Gi0/1 | i rate 30 ...
2
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1answer
68 views

Why switch (2950) port configuration is needed when NIC adapter is configuired?

I have two Cisco 2950 switches connected with a Dell 7810 machine to provide network redundancy. The machine is equipped with one built in (On Mother Board) Ethernet port and with a dual port NIC “...
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5answers
1k views

IPv6 address assigned to vlan interface of 3750 switch changes

When setting up my 3750 stacks, I enable IPv6 on the Vlan1 interface so that I can manage the stack over IPv6. The stacks are not doing any layer 3 routing. However, it seems that the IPv6 address ...
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1answer
44 views

Network Security Tunnel

In the Tunnel Interface, when I edit the tunnel information, it shows: Attributes Values Tunnel Source IF10 Tunnel Destination 1.0.0.1 Tunnel Mode GRE What does IF10 ...
3
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1answer
628 views

Does traceroute show the IP address of the entry port? or exit port?

Does traceroute show the IP address of the entry port? or exit port? For example, if there is an intermediary router in the path with 198.28.56.18 facing the source (entry port), and 65.86.24.136 ...
6
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2answers
1k views

Why is Cisco enforcing X:X:X:X::X for link-local addresses when the standard says FE80:/10?

This document shows that you can use one of these options: interface type/number ipv6 address ipv6-prefix/prefix-length eui-64 ipv6 address ipv6-prefix/prefix-length link-local <------...
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4answers
4k views

Why do I get “% Warning: use /31 mask on non point-to-point interface cautiously” when I use a /31 subnet mask?

Why do I get % Warning: use /31 mask on non point-to-point interface cautiously when I use a /31 subnet mask over Ethernet, and why am I not able to ping from R1 to R2 when both the interfaces have ...
4
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1answer
174 views

EHWIC-1GE-SFP for Cisco 1941

I was able to configure the interface but only the GE port is working, not the SFP port. Did I miss something?
3
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1answer
193 views

OM3 optical fiber 850 nm compatibility with 10GBASE-LRM

I have Cisco equipement with "XENPAK-10GB-LRM" and Optical Fiber Type OM3 wavelength 850 nm. As the LRM interface works at 1310 nm, will it work with this type of Fiber.
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2answers
1k views

How to assign all interfaces in one router to OSPF backbone area?

Is there any command to assign all interfaces in router (CISCO 2691) to OSPF backbone area? I was using this command for each interface. network address wildcard-mask area area-id Where wildcard ...
2
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1answer
750 views

What it means to configure two global ipv6 address on a single interface?

I have seen some network configuration files where a single interface is assigned with two different but similar ipv6 addresses, what is the significance of it, ex : interface te 0/1/0/10 ipv6 ...
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2answers
3k views

Why do routers have only a few interfaces?

Why do routers have only a few interfaces? Since one router interface is one subnet itself, a router given G0/0, G0/1 and G0/2 can only have three subnets. Is it sustainable? How can we go beyond ...
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1answer
25 views

i cant configure the ip adress and subnetmask ,i only have one router “1941” and 2 pc's

the command line is this : Router0(config-if)#ip adress 192.168.1.1 255.255.255.0 the error message is : % Invalid input detected at '^' marker.
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1answer
470 views

How to create interfaces for CSR 1000v for GRE tunnels?

Well, my idea is to connect to 4 CSR 1000v routers in different VPC (without VPC peering). I've basically finished with everything with the pre-configuration creating VPCs, subnets IGW, modifying ...
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1answer
66 views

Multiple Networks on Sonicwall with no access to cisco firewall

The issue im having is that i have 2 networks with 2 internet connections. We now all of a sudden have a POS system handling our network. This system blocks our email and a bunch of pages we use. They ...
2
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2answers
836 views

How can two interface communicate between them with different subnet

R1 and R2 are connected with serial cable interface but both of them having different subnet and i know they will not communicate so what are other options two communicate between them without the ...
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1answer
202 views

What's the relationship of a Router with its loopback interface in logic?

I have a Router1 with a loopback 0 connected to the Router2: the interface brief is bellow: Router1>show ip interface brief Interface IP-Address OK? Method Status ...
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1answer
225 views

How to use“ Multimode SFP GLC SX MMD” in Cisco Catalyst 2960 S connected LAN and single mode OFC network

We have single mode OFC network and CAT 6 CAT5 LAN with ethernet and gigabit Ethernet switches and ordered for "GE SFP, LC CONNECTOR LX/LH TRANSCEIVER FOR SINGLE MODE FIBER OF CISCO CATALYST 2960 S" ...
2
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1answer
670 views

Can not create sub-interface like `interface gigabitEthernet 2/1.100`

I follow a tutorial, there shows the method of create sub-interface: but in my actual situation, I can not do this: Router(config)#interface gigabitEthernet 2/1.100 ...
4
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2answers
739 views

Why the Cisco Router's loopback interface can not be showed up by default?

By default, why the Cisco Router's loopback interface can not be showed up? Router#show ip interface brief Interface IP-Address OK? Method Status Protocol ...
10
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4answers
155k views

What can cause “FastEthernet is up, line protocol is down” on a Cisco Switch?

I wonder what can cause the first line output of the command show interfaces to be: FastEthernet is up, line protocol is down. In other words, Is the cable that is connected to the local interface, ...
6
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3answers
1k views

How not to route on a Cisco router

So we have a router, with a switch card interface, 8 ports Say I have 4 VLANs (A,B,C,D) on it, with 2 switch ports in each. Each VLAN (i.e. all ports) can communicate with each other, because ...
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1answer
93 views

My interface do not have a IP address in a segment, but I can ping the IPs of it

You see, in my local Mac's network interface there is no 172.18.1.*: $ ifconfig lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384 options=1203<RXCSUM,TXCSUM,TXSTATUS,SW_TIMESTAMP&...
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1answer
167 views

Network interface issues an ARP request to get the MAC address of an actively used gateway

My network interface actively uses a gateway to send IP packets to other networks. There is already an ARP entry in the cache for the IP/MAC association for the gateway. Is it normal that my network ...
2
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3answers
61 views

Interfaces named with `ge` represent what?

I see a information: Most interfaces are named according to: - Interface media type (ge, so, at, and so forth) ... I know the so represent SONET, at represnet ATM, but how about the ge ? if it ...
3
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2answers
7k views

Network Daughter Card vs Network Interface Card

I've noticed that when customizing a server for Dell you have the option to select between "Network Daughter Cards" and "Network Interface Cards", as well as a number of others. I've looked up the ...
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3answers
1k views

Empty mac address value [closed]

Is there some MAC address value, that can be used to denote that device does not have MAC set (something like 0.0.0.0 for IP).? I thought of ff:ff:ff:ff:ff:ff, but afraid that it could be meaningful ...
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2answers
129 views

Identify IP of the client causing high interface usage on uplink port

Background: We are observing a high interface load (spikes up to 1G) on a WAN (dedicated link) uplink port of a Cisco switch. How can we find the IP of the client that is causing this high load? I ...
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3answers
1k views

Cisco C3560CX Interface number/name question

The Cisco C3560CX's come in flavors that include 10gbs SFP+ ports (e.g. WS-C3560CX-12PD-S), and also less expensive ones that only do 1gbs SFP (e.g. WS-C3560CX-12TC-S). Documentation shows you can put ...
10
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2answers
4k views

Network Gateways vs Interfaces

When looking at the contents of a routing table section on the Wikipedia article on Routing Tables, it contains a table as an example of a routing table with two headings which have an unclear ...
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2answers
121 views

Why it is neccesary to assign IP adresses to interfaces?

I know this is a very very basic doubt, but never I thought of it in a deep perspective. For example, I am going to use the following scenario: You know that we usually use a /30 mask when you are ...
2
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3answers
515 views

Arista switches- Email alert if interface status changes

I'm looking to be notified of interface state changes on my Arista switches without my manual polling of the logs. For example, tailing var/log/messages, I might see something like: un 29 19:10:48 ...
2
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1answer
438 views

Trunk on the outside ASA interface

I have a topology as in the picture. It is designed to be a factory network. 2 ASAs in a failover cluster border the whole LAN. And it is pretty much clear how to configure them: outside interface to ...
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2answers
352 views

Physical / Virtual Interfaces.

Well, I know that's a simple question for the level of this forum, but yet, I didn't found anything on Google, at least not what I want. I'm studying for CCNA R&S and I just learned about ...
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1answer
102 views

Is TCP checksum verification also offloaded to NICs? [closed]

I understand that checksum calculation at the sender side is often offloaded to the NIC. Does this also happen for verification at the receiving end?
2
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1answer
3k views

Subnetting and switch configuration (CISCO Packet tracer)

I'd like to ask couple questions that I have about subnetting and switch configuration (more about latter). Currently, I have subnetted my network to be on IP 192.168.10.0/29 with subnet mask 255.255....
5
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2answers
526 views

Can a broadcast storm do physical damage to computers and networking hardware?

We had a broadcast storm that went undiagnosed for several hours. After the problem switch was unplugged and traffic returned to normal, we had a handful of machines and switches that were broken. On ...
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1answer
1k views

GNS3 wic vs slot

can any one explain the difference between WIC vs Slot? plus I want to have more L3 links in GNS3 but I cannot have more than 4 on 3725 router. there are two built in plus i can add two NM-1FE-TX in ...