first I'm gonna warn that I'm fairly bad at understanding networking so kinda nervous about posting this.... I'm using NetsimK to study setting up a network for a college assignment, I'm finding it really difficult and my assignment is due in 2 weeks (I can't work on it outside college so essentially I only have 2 days) so I'm in a bit of a panic. I'm trying to mess about with the simulator at home so I don't spend so much of my class time googling how to do stuff.

So the scenario is that I'm setting up an office network using 6 PCs. All these PCs are connected to a 24 port switch. I'ce named these PCs PC1, PC2, etc and manually assigned IPs respectively i.e., etc. For the second part of the assignment, we're supposed to make this network wireless. and this is the part I'm having trouble with, my lecturer is no help as he just brushes off my questions and is really intimidating - I've been trying to figure it out using Google but can't do it. Anyway - lecturer has said that we should add an access point to add wireless capability, which makes sense. Another point - there is no access point in the simulator, even though in my lecturers example screenshot of simulator there was one, so I've used a router instead.

Anyway the problem is that I don't know how to assign an IP and gateway to the switch (I'm not to use DHCP). I can open HyperTerminal and use user and priviledged EXEC codes. When I click "check configuration" on the simulator: enter image description here

My physical topology: enter image description here

Cables used are all straight through cables. I would appreciate ANY help - I hope I've explained everything right and supplied enough information. Edit: I've run a console/rollover cable from PC1 to the router as I can't open HyperTerminal otherwise

  • What is the simulated switch? I'm assuming its a cisco switch as the network simulator states "cisco" however knowing what particular model is being emulated is useful. that being said assuming its a cisco catalyst try the command "ip default-gateway x.x.x.x" where x.x.x.x is the default gatweway.
    – David
    Feb 11, 2015 at 17:26
  • There are also a number of other issues that are present here, A router will not add wireless capability to a network, which you state is one of the requirements. Your output from the check configuration also states, that none of the end devices have a default gateway, and that interface fa0/7 should be up.
    – David
    Feb 11, 2015 at 17:45
  • @David I've sorted your last point, about to set the default gateway too....I can't get an access point in the simulator though. Maybe one of the other routers in the lefthand list will have an access point built in, I'll google Feb 11, 2015 at 21:37
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    Aug 11, 2017 at 4:08
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    – YLearn
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3 Answers 3


You need to set a gateway to all the PC!!!!! When you configure the addressing of all pc, you must set, IP address, Mask and Gateway. Gateway is the only way that your network can communicate with other network, in this case, the address that you set on the router interface connected on the same switch.

In this case, E0(router) should be configured with an IP of your network, and that IP must me configured as gateway in all your PCs.


You don't have to have your switch or wireless AP have the default gateway unless they're performing routing, which, probably isn't the case. Whatever IP address is on the Router's E0 interface is going to be your host's (PC's) default gateway. You'll have to manually set the default gateway on the PC's since you don't have a DHCP server in place to distribute that information. Hope this has helped. Generally, switches will only operate as a layer 2 device (where they don't handle IP addresses, just MAC addresses). If it's part of your assignment, to give the switch an IP address, you'll also have to add a "default gateway." checkout this site for the ip default-gateway command: http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2950/software/release/12-1_19_ea1/configuration/guide/2950scg/swipaddr.html#wp1037806

  • Part of the requirments for this lab specifically is to have the switch have a default-gateway, also it is generally better to list the linked command or pertinent points from the linked document, as links are generally subject to link rot.
    – David
    Feb 12, 2015 at 19:49

If I understand what you're asking correctly...

1) get the IP for the router interface that faces the switch: sh ip int brief or on some models sh int ip brief eg: lets say the IP is

2) connect to the switch, and:

conf t
int fa0/7
ip address ; use any unused IP in your network
ip default-gateway

3) now apply the same IP as the default gateway on your PCs

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