router interview questions
Top router frequently asked interview questions
My router has two protocols (and a "both" option) that I can select when setting up port forwarding: UDP and TCP. What is the difference between these two protocols and when would you select one over the other in port forwarding?
Source: (StackOverflow)
Is there a way to provide user-specific passwords for Wi-Fi, so that different users have different passwords?
I'd like to provide each user with a different password for my Wi-Fi connection.
Source: (StackOverflow)
Not sure if this is the place to ask this, but I couldn't find a more appropriate StackExchange site. I heard that the quality of wireless connection follows the law of the lowest common denominator - meaning that if 10 users connect to an AP at 50Mbit and one at 5Mbit, everyone gets stuck with 5.
[-]
Can anyone, with 100% accuracy, say whether this is true or not? I'm asking because we have 8-10 WRT54GLs on DD-WRT powering our company network, and wired speeds through those APs are up in the 50-90Mbit, while wireless can't seem to go above 9Mbit.
Source: (StackOverflow)
I have a minimal CentOS 6.3, 64 bit acting as gateway with 4 NIC (1 Gbps), each bonded together one for public traffic and other for private, which performs NATing. It has 6 GB RAM and 4 logical cores. We have been using this for the past two years without any problems.
I don't have any experience with hardware routers, but I have heard that they have less RAM and CPU and use flash disks. How can a box with low hardware configuration perform better (as in, handle more concurrent connections) than a machine with more RAM and CPU?
What are the limiting factors, other than IOS using different methods to handle this?
Source: (StackOverflow)
At work, we have two wireless networks (e.g., Work1 Work2); the Work2 is used downstairs and Work1 is used upstairs. However, both are notoriously slow. The connection is better when we are wired in, but unfortunately due to our building being very old and our company growing very fast, most employees are not seated near the walls where the ethernet cables are.
I had Cox, our ISP, run a bandwidth utilization test and it doesn't seem like we are capping out on upstream/downstream, which leads me to believe that it's strictly an issue with the wireless networks (which were implemented before I got there).
The wireless networks are both Apple Airport Extremes. Is there anything I can do to improve the situation for everyone?
Speeds are extremely slow, and sometimes drops out.
Source: (StackOverflow)
We have an OpenBSD router at each of our locations, currently running on generic "homebrew" PC hardware in a 4U server case. Due to reliability concerns and space considerations we're looking at upgrading them to some proper server-grade hardware with support etc.
These boxes serve as the routers, gateways, and firewalls at each site. At this point we're quite familiar with OpenBSD and Pf, so hesitant at moving away from the system to something else such as dedicated Cisco hardware.
I'm currently thinking of moving the systems to some HP DL-series 1U machines (model yet to be determined). I'm curious to hear if other people use a setup like this in their business, or have migrated to or away from one.
Source: (StackOverflow)
We've got a Draytek 2829VN Wifi router and I'm wondering how many concurrent connections I should expect a router of this kind to cope with? We are looking to connect 60 iPads!
I'd also be interested in knowing what might happen when it starts to reach capacity?
Not looking for details specifically for this model, but in general.
Thanks!
UPDATE
Thanks for everyone's help!
We ended up going with 3 wired Cisco AP's, sharing a single SSID across 3 channels.
The venue already has WiFi running across channels 1,6 & 11 (the default it seems) so we've opted for channels 3, 8, and 13 which seems to be working very well, with around 20 iPads per AP.
The iPads then picked up the signal almost immediately, something they were taking in excess of 2 minutes to do when running on channels 1,6,11 due to interference.
Lesson learned : don't assume that setting up WiFi for large numbers of people is easy!
Source: (StackOverflow)
I was wondering if anyone had any experience setting up an environment designed purposefully for poor performance when sending/receiving requests over a network. I'm developing an application and would like to make it robust over extremely poor-performing networks. Does anyone know if it is possible to configure a router to:
- intermittently drop packets
- intermittently introduce latency in packets
- corrupt data in packets (this one isn't required as it would require opening the packet, changing the data, and updating the checksum since the TCP layer would catch this type of issue)
If not possible on a router, would it be possible to configure a computer to act as a router and do this?
Many thanks!
Source: (StackOverflow)
So let's say I have a network of less than 20 computers including a server that needs to be accessed externally. What router/firewall solutions would you recommend? It can be either hardware or software and would need to be able to do
- NAT
- Firewall
- DMZ
- Native VPN if possible
- Some form of network bandwidth monitoring
Update: I've accepted the answer I liked but this question probably doesn't have a definitive answer, it would depend on your requirements. Please leave more suggestions with an explanation as to why it works well in your situation.
Source: (StackOverflow)
I am a developer and haven't dealt with server admin or networking in years, so "rusty" is very generous. I am setting up a new web server cluster (starting with two 1U web servers and one DB server). As I haven't done this in a few years, I don't really know what options are available today.
I would like all in one device:
- Small, basic gbit switch
- Small, basic firewall
- Small, basic router/DHCP/gateway
- Small, basic VPN access
- Fits in a 1U space
Something simple with a minimal web interface I can set up and then forget about - 2 steps above a home router device, I suppose.
Edit: the initial reaction from sysadmins is often "no way" because to them, devices that do all this are usually crap. Please realize for my purposes, that's currently OK. My setup (and budget) are just not big enough to justify dedicated equipment that does this stuff really well. I just need something that does this stuff at all.
Recommendations?
Source: (StackOverflow)
On arch Linux, I would like to mainly have eth0 (connected to bridged router) share the connection recieved from wlan0, Ive read tutorials but I'm not command sabby as other users are and don't completely understand. I would appreciate some help! Ty!
Source: (StackOverflow)
I'm building a router out of a Mini-ITX pc + compact flash card setup and I'm trying to choose a suitable distro. My criteria are:
- Must be able to run from a CF card (so no excessive disk writes)
- I'm mostly interested in having a high powered router for the purpose of traffic shaping
- That said, I'm also interested in using this to learn more about how routing / networking works (my original plan was to use a basic bare-bones distro like LFS and put the routing software on top myself) so I'm not after a distro that hides the inner workings from me
- I'd also like to have SSH
I think I've narrowed it down to two - Monowall and pfSense (pfSense being a fork of Monowall)
Monowall has the advantage of being targetted towards flash cards, wheras pfSense has more of the traffic shaping and other features I'm interested in.
I also understand that they use different mechanisms unerneath the covers, but I cant say I understand that much about the differences to make an informed decision.
Does anyone have any advice / information on either of those (or another alternative I havent yet considered)
Source: (StackOverflow)