Questions tagged [router]

For questions about network routers, devices that forward data packets between computer networks, commonly at the network layer (layer 3) of the OSI model.

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33 views

Apply Interface Default Gateway to Entire Device

I feel there may be a very simple term for what I trying to do, but I'm not sure what it is, and it is difficult to search for it in concise words. The shortest description I can come up with: "I ...
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0answers
15 views

Cisco 2960 and Cisco 871 - no connectivity on non-default vlans

Unable to get internet connectivity from non-default vlans. Suspect router config is not adequate Five vlans created on 2960 (10,20,30,40,50)and Gig port 0/1 set to trunk. Port f0 on router which is ...
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2answers
15 views

How does DHCP work?

I'm carrying out an experiment to test the mechanism behind DHCP. In this topology, I disable the link between the switch and the router. However, the computer still request IP address successfully. ...
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0answers
17 views

Can your router make backups? [closed]

suppose I 3 VM's connected with the virtualbox-host-only interface, I configure one VM as the router with also a bridged adapter connected to my outside network, one webserver connected to the virtual ...
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0answers
24 views

Wich setup should I use? [closed]

I want to gain some experience setting up a network, but I am already in a network wich I can't play around with (setting up firewalls, dhcp servers etc.). I'd also like to create a webserver, assume ...
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1answer
37 views

Will 2 redundant Routers configured with HSRP consume 3 IP Adresses in each Subnet?

The Problem occured while studying for my exams Problem: I have to design a Network for a Company. The given IP Adress Space is 192.168.1.0/24 which has to be divided into 4 Subnets. These Subnets ...
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2answers
68 views

How to access Cisco 2500 series admin GUI interface with known IP address when Firefox/Chrome state connection cannot be reached?

I know the username and password of my Cisco 2500 series wireless & ethernet controller and its IP address, but when I enter the IP address into a web browser (Firefox and Chrome) it states the ...
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4answers
152 views

Multi LAN network does the main router to the internet need to be in its own subnet?

I have to design a network where there are 4 within which are different number of VLANs with varying number of hosts per VLAN depending on the building. My confusion lays in the main router, does it ...
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5answers
791 views

Different Behaviour of a Router

There are 2 cases that I would like to point out: When the router is directly connected with 2 PCs like this, In this case, PC2 is able to ping PC3. I just configured the IP address of PC2 and PC3 ...
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3answers
35k views

Why is 192.168.1.1 the most common default router gateway? [closed]

Why does most routers has default ip gateway 192.168.1.1? How do I change the gateway? If it gets changed, does every pc connected get a modified ip?
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3answers
1k views

OSPF Configuration: Router ID won't change to loopback address

I am new to this so forgive me for mistakes, but I feel like I am missing something here. I am trying to use a loopback address as the router ID for Router0 in my network. I am typing in: Router(...
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1answer
37 views

How can someone connect to my computer even through port forwarding?

If I set port forwarding up on my router to redirect connections on port, say, 50000 to my computer, how can someone connect to my router in the first place ? Does that mean that my router has a ...
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1answer
196 views

Duplicated Vlan ID

I have one flat network with our data center and it is causing as a lot of issues, so i had to design a new network to separate the buildings from the data center, when I designed the new network i ...
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1answer
50 views

Why use subnet mask /30 for the internet port of the edge router? [closed]

In the following network, why should we pick the subnet mask /30 for the internet port of Edge Router 1? Since the wireless access point Edge Router 1 needs to connect to 3 hosts in LAN 1, a subnet ...
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2answers
89 views

Can two or more computers that are physically close together form a connection/network without a router? If they can, how do they do so?

So, I am pretty familiar with things when a router is used. To my knowledge, packets travel from Computer A to the router, then the router directs it to Computer B. Problem solved. I get confused when ...
0
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1answer
32 views

How does a packet know where its destination is? [duplicate]

When I connect to my friend's mobile Wi-Fi hotspot, we both have the same public IP address. Now, when I go to duck.com, how does DuckDuckGo know where to deliver the packets? I mean, I and my friend ...
23
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5answers
52k views

Why use iBGP inside an Autonomous System, if IGP protocols fulfill the need for internal communication

Can anyone explain why we need iBGP for the routes when we have the IGP protocols (OSPF, RIP) for internal communication within the AS? I have read a lot of articles and books, but I could not find ...
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2answers
63 views

How does one determine what the default gateway should be in a multi-router setup?

Trying to set up a network with multiple routers, very similar to what's depicted in this diagram from the FreeBSD handbook: In particular, regarding this specific diagram, what should the default ...
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3answers
180 views

Router interface on same subnet

Could someone please explain why can't be have 2 interface on same subnet? Do router use network address to forward traffic?
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3answers
226 views

Why does OSPF use flooding despite using multicast?

We know that flooding is only possible in layer2 switch. But in OSPF router in layer3 uses flooding with multicasting. Suppose we have one router in OSPF uses multicast address 225.0.0.9. If router ...
0
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1answer
21 views

Does a WiFi client vary the strength of the signal it emits? [closed]

I am using a metal container to dampen my WiFi router in the hope of reducing its radiation health risks. I'm wondering if the client device might increase its own emitted signal strength to ...
1
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1answer
60 views

can't ping the WAN IP of a router

I learned to use cisco packet tracer and found something confusing but actually this is not about the cisco packet tracer . I'm curious if this apply in real network as well. So i tried building this ...
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2answers
46 views

How does a border router work

Supposing, we have following pieces in a theoretical network architecture Network A: A low power IPV6 wireless network Some low power hosts: Low power devices which are connected to the above low ...
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1answer
32 views

Cisco 2851 Static NAT Entry - Similar Static Entry Already Exists

Thank you in advance. I have a few 2851 Cisco ISR. This is my NAT Pool config; ip nat pool NAT-Pool 38.xxx.xxx.193 38.xxx.xxx.206 prefix-length 28 ip nat inside source list 1 pool NAT-Pool overload ...
9
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1answer
2k views

How much RAM you actually need to keep whole global BGP routing table?

It seems that different sources claim very different RAM consumption for having whole BGP routing table information in RAM and having the router to correctly route the traffic. According to ...
0
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1answer
41 views

How can I set up two sub networks that can communicate by LAN but where only one has internet? [closed]

With only two routers, where one has a connection to the internet, is it possible to set up a second sub network that has no access to the internet, but where devices connected to either router can ...
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3answers
668 views

static route distance value fail over

Config: ip route 172.27.8.17/32 172.24.0.141 ip route 172.27.8.17/32 172.24.0.102 2 Result: show ip route 172.27.8.17 Routing entry for 172.27.8.17/32 Known via "static", distance 2, metric 0 ...
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1answer
47 views

Does a router work both on Layer 2 and Layer 3? [duplicate]

According to TCP/IP model router works at Layer 3. But when data has to be transmitted to different network it is based on IP address but hop-to-hop transmission is based on MAC address. That means ...
3
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2answers
391 views

Why the two connected routers via PPP doesn't use ARP but ethernet use ARP?

I have read from @Ron Maupin's answer of this question that your two routers are connected via PPP (this is not uncommon), ARP will not be used , but if the two routers are connected via ethernet, ...
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1answer
73 views

SD-WAN os to IOS-XE

I am trying to convert currently running SD-WAN os to IOS-XE on ISR 1100. Can anyone know how to do that? I went through some of the CISCO documentation but could not find anything effective.
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2answers
100 views

Can I backup config of an EdgeRouter Lite 3 to an EdgeRouter 4?

After having worked 6 years and 24/7, my EdgeRouter Lite 3 have definitely died. I want to replace it by a new EdgeRouter 4. Can I easily use my EdgeRouter Lite 3 backup files and import it to a new ...
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2answers
97 views

Why router can't be used for converting different model of network but gateway can do this?

We know that Router can't be used for converting different model (e.g OSI model to TCP/IP or TCP/IP model to OSI) of network. It isn't a multiprotocol converter. But gateway is a highly sophisticated ...
2
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2answers
362 views

In tunneling, how destination routers identify if a packet is encapsulated?

In tunneling, a packet gets encapsulated in the payload section of another packet. If the router at one end encapsulates the packet, then how the router at another end identifies whether the packet is ...
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2answers
82 views

How in Distance vector routing one router communicates adjacent router through broadcast address and OSPF uses unicast with another?

In distance vector routing algorithm one router can communicates(shared the routing table) with adjacent router by broadcasting message which are in same subnet. OSPF uses flooding to unicast message ...
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2answers
166 views

IOS Memory allocation error after ping

I have written a script in Tera Term for a Cisco IR809g which pings 3 different routers(IR 809g) in 2 different networks over the cellular interface. After +- 6 hours I'm getting a Memory allocation ...
6
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3answers
16k views

When exactly is ARP protocol is used

I am a quite a beginner in network engineering so please be nice. I am not sure I understand how ARP protocol works in some situation. For example, if we have following problem: ARP cache is empty ...
0
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1answer
57 views

Does router handles directed broadcast on same network?

I have started reading on Computer Networks recently(beginner), and have come across some of the doubts regarding how the broadcasting is handled by routers and switches. Assuming there are no ...
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0answers
18 views

Personal VPN sub-network accessible through Work VPN? [closed]

I currently access my work network via Cisco VPN. At work, I have my own three computers and NAS on a personal dedicated router using my own DHCP. For several reasons, I do not want these computers to ...
1
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2answers
383 views

Why logical systems?

Juniper supports partitioning of a physical device such as a router into multiple logical systems. Each of these systems could have their independent routing/switching tables depending on the logical ...
3
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1answer
81 views

why can a router make two PCs in different subnets access each other?

Case 1: PC A: 192.168.1.2 / 24, and it connects to LAN port1 of router A PC B: 192.168.2.3 / 24, and it connects to LAN port2 of router A Given above we know A and B can't talk to each other due to ...
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4answers
38k views

Cisco Router Telnet Connection Refused

I have a cisco 1941 router just configured but no matter how I go about configuring the telnet, it seems not to work. It has interfaces already set up and systems can browse through it in the office....
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1answer
38 views

What's the procedure to limit a subnet on a Cisco router from seeing another subnet when both are using NAT?

I have a Cisco 891F router. The internet is hooked up to G8. The student network is Vlan 200, and the Office is Vlan 100. (I know the internet has an internal subnet (192.168.1.5), but that's because ...
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2answers
231 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?
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1answer
39 views

What exactly defines a WAN?

I've found this question but it doesn't seem to answer my question. What is the "technical" definition of LAN and WAN I know that a Wan consists of more LAN's together and MAN's and it's ...
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0answers
18 views

What really a point to point connection means? [duplicate]

I know that point to point connection is used to directly connect between two nodes without any intermediate. But if we take in our world the internet(WAN) , let's say I want to achieve a point to ...
0
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2answers
64 views

RSTP Separation

Topology: (Ring Network A)----[Router A]-------(Possibly Ring Network C)-------[Router B]----(Ring Network B) Goals I need Router A to always be the RSTP root bridge for Network A. I need Router B to ...
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0answers
45 views

WAN ip address looks like private ip, but whatsmyip shows a public ip address [closed]

Let me preface this by saying that I'm not very good with internet networking, but I tried my best to gather information. So I've been meaning to do some port forwarding to open a server, but I got ...
7
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3answers
5k views

OSPF and its use of Multicast

When it comes to OSPF and its use of multicast, am I correct in believing that IGMP forwarding and an IGMP querier is still required within the local segment? My understanding would be without this, ...
1
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1answer
59 views

Must the host IP be contained in Router's subnet?

The settings are: manually set my host IP: 10.0.1.6/24, gateway: 10.0.0.138/24 they both know each other's MAC (arp -a shows the list) and there is a direct physical connection between them. From the ...
0
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1answer
39 views

How to manage firmware

Switches and routers have some firmware (similar to BIOS (UEFI) on PC). It represents a "step" before the OS (maybe I'm wrong). Can we manage this firmware just like BIOS or UEFI on a PC? On ...

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