Intermittent internet access on a flat network - Router is connected

Question

I’m looking for some help with network settings. I’ve just started a new job (non-IT!) and we have problems with our office network. I’m the most IT literate in the organisation (15 permanent employees) and so have been dealing with IT issues. Our main bit of software is web-based so we need constant web access but it sometimes goes down for between 20 minutes and 3 hours despite everything seemingly working fine.

It’s a flat network with wireless APs, BT Business Broadband 8Mbit connection and that’s about it. We have no servers and no standard settings and staff are encouraged to bring in their own laptops and connect! The network basically exists to provide internet access and that’s it. We also have students accessing the wireless (and I know there’s a whole list of access and content issues etc but right now we just need internet access stabilised).

This is what we have:

Building 1 Cisco SLM-224P 24-port PoE 10/100 switch with 2 gigabit ports 3 x ZyXEL NWA-3160 wireless APs Samsung OfficeServ 7100 phone server which borrows the building’s wiring

Building 2 Netgear GS605-UK 5-port 10/100/1000 switch 1 x ZyXEL NWA-3160 wireless AP 1 x BT Business Hub – 2wire BT2700hgv – is the DHCP server

We have 2 link cables between the buildings. One connects the two switches on a gigabit port. The second (oddly) connects the switch in building 2 to the OfficeServ server in building 1.

When the internet goes down I can still access the router through a wireless connection. I can also ping websites and get a response. Firefox just says “Cannot connect” etc. The system then heals itself when it feels like it.

(Sorry if this is asking too much but) These are my immediate questions…

1. Why would browser-based internet go down? I don’t know enough about protocols etc but I can try to standardise settings.

2. The WAPs have a DNS server setting and I don’t know whether it should be “None” or “From DHCP”.

3. What should be the DHCP server? The router or the Cisco switch? Or something else?!

4. Would there be any problem in connecting the second link from switch to switch? Is that good practice?

5. Is it worth swapping the Netgear GS605 with either a Cisco SG200-08 or Netgear GS108T-200?

6. Is it worth upgrading the router to, for instance, a Cisco RV042G Dual Gigabit router which would also act as a switch? Or is it better to have a separate router and switch in Building 2?

Answer 1

There are too many variables.

Example of variables includes: Quality of cable, quality of cable runs, quality of end termination, VLANs in use, port security in use, total number of users, bandwidth used, QoS settings, DMZ configuration, firewall intentions, et al.

Using consumer grade equipment for commercial business purposes has this manner of robustness issues. That is, the equipment does need to be power cycled to restore operation.

Answering:

1. Lack of connectivity could be from link saturation

2. From DHCP. Assumes there is rogue DHCP protection. But, really should be on own VLAN to restrict from internal traffic.

3. Depends on what is desired from DHCP. IP reservation, BOOTP, and advanced features would require a proper DHCP server.

4. There is a length restriction of 100m (or 300 ft) when using copper cable.

5. Cisco would be a "better", but neither is commercial grade.

6. Each building should have a dedicated switch with a point-to-point connection.

Would indeed highly recommend finding a Cisco CCNP or network administration professional to consult. Have the layout documented, along with physical map, and passwords also documented (not default). The one question prospectively has a hundred more implied to go with it.

Good luck!