nei1,
Q1. Why are Channels 1 and 11 preferable? I assume the microwave ovens are centered in the middle of, and are making noise all over Channels 2 through 10? <snip>
A. First, a good picture of the channels:
Microwaves are fairly narrowly centered on the frequency of the Brownian motion of water at 2444 mhz. (Which would bother 7-9 the most). Phones and other Spread Spectrum devices have two issues: they are channel specific while on standby, although most use channels between 2 and 10; and when in spread spectrum mode while being used can cause problems from their proximity as well as their use of a spread of channels.
And not all are alike in how much of a problem they cause.
And to further complicate things, the FCC has limits on the output power by channel, they are not identical; you want to pick channels that allow some room for additional access points in the future; and nearly all wireless routers come with a Factory default setting of Channel 6, so it quickly becomes "crowded."
Channels 1 and 11 for all of these considerations has shown for the moment the least troublesome. If everybody starts defaulting to 11, I guess I will have to start recommending another channel. There is more practical advice in the recommendation than any other factor.
Q2. How does interference contribute to the modem crashing? If interference slows communications to a crawl, the modem should be happy not to have to work so hard...
Interference has nothing to do with the modem.
Q3. How does using "linksys" as an SSID contribute to the modem crashing? <snip>
A. Again, nothing to do with the modem. You were asking about instability later in a general sense. The War Driving community has surveys that show approximately 80 percent of wireless routers and access points are using the manufacturer's default SSID.
There are not only good security principles at work in changing the default SSID, but it confuses the heck out of client adapters as they feel compelled to "roam" these points of presence. In high density (in a wireless sense) areas the adapter can become nearly completely pre-occupied with comparative sampling of access points. High end, and increasingly SOHO routers offer the feature to reduce output power on the access point to help prevent coverage overlap and consequent adapter association confusion.
Q3. How does enabling DHCP contribute to the modem crashing? It doesn't. There are usually two seperate processes of DHCP discovery going on:
A. The WAN side of the router often is set to use DHCP to discover an IP from the ISP. Most of the SOHO class router DHCP problems with router firmware are due to failures on this side of the router; in particular, renewing an IP lease when the original expires. There are some router firmwares that fail on the LAN side with lease renewal to the clients, although this is less common. And of course, there is at least one Linksys router (not the WRT54G) that is fairly famous for failing at both DHCP sides in lease renewal. But the modem could care less.
In general the DHCP service is sufficient and reliable on these routers. There are some features I wish they had, such as IP reservation, but you cannot have everything.
Q4. Been looking around DHCP. My router is using the function to assign IP addresses to the connected computers. Will anything work if I disable this function? and how does it contribute to instability? Also, can't find the function to select Router vs. Gateway.
A. The Gateway/Router choice is under Advanced, DNS on your router. For small networks DHCP is a convenience, it is easy enough to just use static IPs. If you have special Port Forwarding needs, it ensures that over time your forwards will go to the right machine. There are several wireless adapters, and their driver software, were from experience people have learned it more reliable to use static ips. I know of no issue with the WRT54G with DHCP on the LAN side, but I also know that there are several 802.11b adapters that just work better set to static IPs than dynamic ones obtained from the router.
