Lynksys Wireless Router/Modem

That couldn't be any less clear.

Which is it,a table or a program? If it's a program, what program are you talking about? If it's a table, what properties does it have?

What is a 'constant' IP address? Is that a static IP, or does constant mean the same dynamic IP always gets assigned from your table/program?

And how are you assigning an IP to 'the programs'? Applications typically don't know or care about IP addresses.

Finally, what does 'based on MAC and client ID' mean? The MAC address is self-explanatory, but where are you getting a client ID and what are you using it for?

You're translating one IP address to another? Mapping, translating, NAT, or what?

How does 'the program think' it has either type of IP address? Again, programs don't know or care about IP addresses. What, exactly, are you trying to accomplish with all of this?

Nope. Both my neighbors, customers, and my own systems are in a near constant state of change. New gadgets appear all the time. It's not unusual for me to dump the DHCP lease table and find 20-50 IP addresses in use [1]. I create most of the changes by dragging home customers computers and doing endless updates while doing something else [2].

Most of my customers are similar. Wi-Fi enabled devices come and go. Blackberries, iPod Touch, laptops, game machines, weather stations, IP cameras, VoIP phones, Netflix receivers, Blue Ray players, etc are common. If I ran my customers as an all static IP system, I would constantly be running around making changes and playing IP administrator. Incidentally, this is why using MAC filters for wireless security is a lousy idea. Every time something new needs to be added, the admin has to enter the device manually into the MAC address filter table.

If you're running an ISP, Wireless ISP, or neighborhood wireless LAN, that's exactly how it's done. My biggest IP assignment headache are VPN's. The Class C blocks at both ends of a VPN should be different. That doesn't work when every home network on the plant seems to be on

192.168.1.xxx or 192.168.0.xxx. It's all too common to get a call asking why someone can't login to a VPN from home. I usually change the Class C IP block on the home network to something else, although sometimes, it's better and easier to change the office IP block. For example, my office LAN is on 192.168.111.xxx.

I just morphed into 62. Six more months and I become a drag on the Social Security system. Three more years and get to help drain Medicare.

[1] It's a pain in the posterior with DD-WRT because it uses micro DHCPd. Grab the /tmp/udhcpd.leases file and copy it to a desktop machine. Download dhcp-lease-list PERL script:

and you should see the leases in human readable form. Also see: /tmp/udhcpd.statics which is the table of pre-assigned DHCP leases. At least it's in human readable form. My home DD-WRT router shows 18 leases and 6 pre-assigned IP's, for 4 days uptime.

[2] Don't try to do anything that requires thought or intelligent decisions while riding an exercise bike.

That might be the norm for you, but it's not even close to my experience out here in the Midwest. The people I deal with will typically add or replace a PC every 2-3 years. Desktop systems are still far more common than laptops, so mobility isn't a big deal. Most people I know with a laptop wouldn't dream of taking it out of the house. If I were dealing with a "near constant state of change" I might look more favorably to DHCP myself, but that's so not the case here.

It's a disadvantage for home networks

For example unless Microsoft have changed the way network attached printers are handled in Windows 7, they are configured by a wizard that searches the network for printers and remembers the IP address instead of a URL.

I've got a Brother Laser and an HP Photosmart both of which include their own print server and wired ethernet connection to the Router.

If you don't give the printers fixed IP address it won't find them if devices are powered up in a different order. Which they always are.

Torrent handling wants port forwarding otherwise many remote servers throttle downloads because fairness means ther people download from you the stuff you've just downloaded from somebody else.

This is done by IP address not URL. So more fixed IP addresses apart from one machine which never runs torrent software.

The PCs won't automatically reconnect to my D-Link network attached RAID disk box if its IP address changes because that's what the D-Link utility uses.

All of which I found out the hard way. I don't need to deinstall and reinstall devices on several machines when they're powered on in a different order.

End result: everything apart from one elderly PC needs fixed IP addresses.

I suspect business networks have PCs for dedicated printer and disk servers with rather more sophisticated software than comes built into the sort of kit we have at home. And they probably don't run torrent software so the result is different.

I don't know, I see advantages for some situations, like very small networks or Jeff's constant change scenario, or perhaps situations where the network owner would rather put up with the hassles you identified in this post instead of the hassles of static assignments. Sometimes it's almost an even trade-off. In the end, I suppose it's a personal choice as much as anything else. For me in my situation and I think you in yours as well, static assignments make the most sense.

I don't power down anything except a laptop, so I don't have a reason to power things up in any specific order. Actually, I'm surprised that you power cycle things like print servers and NAS devices. I don't do that here.

Perhaps you don't live in a place where the utility cables run through trees?

We lose power in thunderstorms, ice storms and high winds.

But in any case it is bad software design to use fixed IP addresses where URLs are available. Whether it is in Windows, the router or the built in print and disk servers.

Without fixed IP addresses I would have to deinstall the networked devices on each comupter and reinstall them. Also change the IP address at ther router for the forwarded port.

When I've got more important things to do when the power comes back up, like catching up on lost time. I suspect the problem with the printers is that if I had two identical Brother Lasers instead of a Brother and an HP Photosmart they would default to the same ID based on the model number and the wizard could not tell one from the other.

Possibly also with the disk box.

Even though I should be able to install one, log on to it and change its name.

But there is absolutely no reason why I shouldn't be able to specify port forwarding on the name of an attached device rather than its IP address.

We had a huge ice storm in 2005 that knocked power out for 5 days, but I don't remember when we lost power before that, (I've only been living here since 2001, so not that long), and we haven't lost power since then. Our utility cables are all buried.

Well, things are about the same on the left coast. The average lifetime of a desktop is about 3 years. Laptops last about 1-2 years before they are either destroyed or stolen.

So, how many wireless devices do you own? Cell phone, PDA, laptop, desktop, game box, print server, Netflix, internet radio receiver, etc. My guess is the average home system has about 6 wireless devices and growing at the rate of adding 2 additional devices per year. With

6 devices, and a 2 year lifetime, that's one device either added or replaced every 2 months. Of course, it's not evenly distributed and tends to cluster around birthdays, holidays, and Apple product releases. Reconfiguring the static IP's every 2 months isn't too horrible, but at the rate of adding 2 new devices per year, in 3 years, the rate will increase to once per month. That's a PITA.

Personally, I've settled on a compromise. Many routers allow for "pre-assigned DHCP leases" or the oxymoron "static DHCP". The device is configured for DHCP, which makes setup trivial. The router has a table of pre-assigned MAC and IP address pairs. If I need to physically move the device or laptop to my office for repair, I don't have to reconfigure the device or laptop. If a visitor shows up with a cell phone, PDA, laptop, or game machine, the owner does not need to do anything to the wireless router for it to connect and work.

Baloney. The "problem" is that your unspecified model router does not save the DHCP leases between reboots. Many routers do save these leases and work as described in RFC2131: Retain DHCP client configuration across server reboots, and, whenever possible, a DHCP client should be assigned the same configuration parameters despite restarts of the DHCP mechanism,... Most cheap wireless routers don't bother to do this, causing the problems you've described. DD-WRT does, but I have it disabled in high traffic routers because I'm using pre-assigned DHCP leases, and if the leases are not expired quickly, the DHCP lease table will rapidly fill.

Small businesses resemble most home systems in both selection of cheap hardware and lack of sophistication (and sloppy wiring). There are plenty of print servers around in my business customers (mostly HP JetDirect variations). Some are setup with static IP's because some (not all) of the HP JetDirect client software works by IP address, not NetBIOS name. If it recognizes the NetBIOS name, the JetDirect card gets configured for DHCP. When lazy, I use pre-assigned DHCP as a compromise. I have a few wireless print servers at some customers, but I avoid wireless printing if possible.

Sigh. I have several customers that distribute their catalogs and software via a BitTorrent NAS server. It's a Buffalo Linkstation something with built in Torrent server.

My only wireless device is an Ethernet bridge. I have a laptop, but I can't remember the last time I booted it up. It's older and doesn't have wireless capability built in.

Come on, configuring a new device takes what, a minute or two? On the PITA scale, that doesn't even register, especially when it's happening only once a month or so.

I do a subset of the same thing. My networked devices don't leave the house so static assignments work best for them. Pre-assigned DHCP leases would just be more work. However, when I bring someone else's equipment here for repair, if it's configured to use DHCP it just works, and if not then I need to configure it twice, once on arrival and once more to put it back before it leaves. So yes, there's a DHCP server running on my network, but I don't use it for any of my own equipment.

One size does not fit all - never has.

With DHCP, you are depending on the DHCP server configuration (defaults and local settings). If they work for you - that's fine. You are trading the complexity of setting up the DHCP server verses setting up the client[s]. The brain-dead mode of "hand out any address to any computer that asks for one" may not be optimum, which is why most DHCP servers can be set to hand out specific addresses to specific systems (generally based on MAC address). "Pay your money - take your pick."

Trivial solution - DHCP servers can assign specific IPs based on MAC addresses. HOWEVER, you do have to configure it to do so.

The big HP printer eats lots of power - but it's fast. The small HP con$umable$ are expen$ive, but it only uses a few VA when idle. The ancient dot-matrix is dirt cheap, slow, and wants about 100 VA when it's waking the dead. How often am I printing? ``That depends.'' Bottom line is that all of the printers are not on 24/7/365.

Trees... yeah, I remember those. We also have drunk drivers who manage to drive into the surface mounted transformers and telephone distribution boxes. So? There are two UPS here, powering nine computers and the networking stuff. If power fails, the computers will turn themselves off gracefully after a few minutes.

Huh?

DHCP has been able to allocate IP addresses based on client MAC address since 1993 (RFC1541), as did the earlier BOOTP from 1985 (RFC0951). These protocols were developed at rather large universities, and they did really think about consequences of fixed verses dynamic addresses.

What do you expect to do when we've got some 40 identical printers on this floor of this building _alone_ (differing of course in their physical location)? Sure, we use static IP addresses (which implies static names for each printer) but as I've been saying, DHCP can be configured that way.

Old guy

In this case, you're a shop and I wouldn't expect things to be anything like normal.

I've got a DHCP server available (intentionally not running by default and not running on ``my'' network address range), and needed it just once last year when relatives visited.

but think of the money you could be making (use a student intern if you're pressed for time) ;-)

[compton ~]$ whatis arpwatch arpwatch (8) - keep track of ethernet/ip address pairings [compton ~]$

Depends on your paranoia level, but MAC addresses are not infallible as you know well.

Most home users aren't. Actually, I'm slightly surprised you aren't using LinkLocal (RFC3927 - 169.254.0.0/16) for this.

"seems to be" I think that's the only address range anyone knows about. Of course, they also miss the secret address range used by every ``hacker'' and skript kiddiez 127/8 ;-)

NOT recommended if you can possibly avoid it, as that _permanently_ cuts the amount of eagle droppings by 30-ish percent compared to waiting to 66. Consult your financial/tax advisor. SSA should be mailing an annual statement of projected benefits that will show the horrible truth. I've past 70, and am still in harness, but that's also because my older sister explained that mortality rate increases if you start goofing off - never mind the arthritis and what-not.

DO apply for part A (hospitalization) at 65 - there is no cost if you've been ``contributing'' to Medicare. Part B (doctors) and D (medications) on the other hand cost (minimum $96.40/month) plus co-pays, limitations, exclusions, and other hoops. Oh, and contact SSA 3-4 months before you turn 65. If you're going to retire, contact them 3-4 months before you do as well.

It's no worse than a real bike riding out there where the idiot drivers can see you. If you do, don't wear the Spandex costumes. It makes everyone laugh and they may loose control of the car and blame you for the result.

Old guy

True for myself. However, I was also referring to my customers. What frequently happens is someone sets up a wireless router and mistakenly applies the commonly available advice to apply MAC address filters for all their devices. This usually happens around Christmas. When a new device arrives, the original perpetrator is not available, the documentation was missing, or nobody even remembered to scribble down the router password. I arrive, and there's a working router, and nothing else. If I'm lucky, I explain the situation to the customer, who invariably says "do what's right and don't bug me with the techy stuff". What's right is DHCP for everything, with pre-assigned DHCP addresses for fixed devices (printers and servers). Such calls were especially bad last year, where I was doing about 2 of these per week during Easter vacation. I expect less this year as users are ignoring web security advice and routers are arriving slightly more secure and easier to setup.

I'm paid to solve problems, not create or perpetuate them. Student interns are great for digging ditches, running wires, and cleaning up my office. Asking any more would be risking my sanity. Besides, if I created an employee relationship, the paperwork, taxes, and insurance would be unaffordable.

I use scripts based on arpwatch on some systems. The problem is that nobody is reading the reports or looking at the output. It's like a burglar alarm without an alarm bell.

I've seen those. Not all devices and operating systems will default to 169.254.xxx.xxx if they can't find a DHCP server. I also have my laptops set to default to 192.168.1.xxx so that I can configure routers without having to waste time setting up a static IP address. (Yeah, I'm lazy).

I've seen traceroute results from major corporations where the path goes through RFC1918 non-routeable addresses. It's the router manufacturers that drive me nuts with the overuse of 192.168.1.xxx. At least Belkin and a few others user 192.168.2.xxx which allows VPN's to properly function. There's no reason the Class C part of the address can't be random (0-254), but that might create some confusion.

It's tempting. However, with my assortment of medical problems, I don't expect to make it much past about 75. Based on a fairly short collection rate, 5% inflation, 10% time value of money, solvency of the Social Security system, etc, my back of the envelope calculation suggests that cashing in early is better. I'll grind the numbers in an organized manner and post them when I have time.

That's me. I lie on my own taxes and I'm rather bad at taking any financial advice. That may explain why I'm not bankrupt.

Yeah, I get those statement of benefits every year in about February. I can't wait.

It's true. I've seen it happen. Retirement and boredom kills. However, please continue working and paying taxes to support my impending retirement. Incidentally, my family has a track record of having a heart attack, stroke, or dropping dead on the job. It's become a tradition, where I'm expected to work until I literally drop.

I have 5 bicycles but have had past difficulties riding them due to various ailments. The trick is to get into shape before summer, which is what I'm trying to do. It also wouldn't hurt to loose some mass. I don't do Spandex. Image, perception, and first impressions are everything. I've already had my bike versus Oldsmobile engagement and lost.

Obviously you know your customers (and that really does sound about normal).

Hope no banana slugs are listening.

I was under the impression that the school handles that, and basically you are paying less than cost to the school. But I'm also aware that the UC system isn't exactly over-flowing with cash.

I know commercial *nix don't but I thought most of your dealings were in windoze and a bit of OSX.

Nothing wrong with that - for the most part, customers are not expected to connect to those systems, never mind outsiders. Recall that real IPv4 addresses are a valuable commodity, so why waste a world reachable address on something that doesn't need to be reached from the world. I know several ISPs that are using RFC1918 addresses for the ``internal'' services meant to be available only to directly connected customers such as mail delivery and customer support.

Obviously the major confusion comes from the ``knowledgeable'' customers who know that it must be 192.168.1.x - I think there's some RFC that requires it - maybe it's a gummint law... ;-)

[SSI]

Five???

Recall there was no cost-of-living increase this year. I've been hearing all about it. On the other hand, Medicare fees went up, and there is lots of talk about drug prices increasing. Some have mentioned changing from a tiered fee (generic, preferred, the_rest) for meds to a tiered _percentage_ of sale price.

I imagine you've also got an individual health insurance policy at best (Blue Cross or equal). Be aware that Medicare doesn't cover a number of things you may be used to - annual exams for one example. I'm currently seeing a primary care and five "*ologists" and the co-pays and deductibles mount up. At least I can get four of the eight meds I'm on at the local druggie for under five bucks a month each.

She's moaning because she finally retired at age 74.

Ahh, the company no longer has "mandatory" retirement age, but I'm expecting to get thrown out on some other excuse.

Oh, like my father (56, heart attack), oldest sister (57, cancer), and most uncles and aunts? Ask me why my breakfast is nine pills and I'm seeing some specialists quarterly (yes, one of the meds is a baby aspirin every morning). On the other hand, my other sister is still kicking at 75, and my mother made it to 90. Obviously you should be seeing the local quacks - heart attacks and strokes are preventable. As for dropping dead, don't annoy the local mobsters.

You've got the cooling breeze from the Pacific - here, summer means it's still over +40C/104F at 8 PM. Of course, I don't have the hills to worry about, but it does keep the cardiologist and pulmonologist happy. Two one-liter water bottles - don't get very good mileage.

Yeah, I get screamed at about that on a regular basis

We've got a fair number of health freaks cyclists here, and I don't like hearing them snicker when they pass. I'm usually in jeans and a full sleeve shirt to keep the dermatologist happy.

State law says cars must clear bikes by three feet even when there isn't a bike lane marked. Right. I've been sideswiped twice, and blown over with the wake turbulence once. I stay off the "main" streets, even though several are well marked with warning signs and have bike lanes. Back streets are _slightly_ less dangerous.

Old guy

They're listening. I have an unusual problem during the wet winters. The banana slugs somehow get into my downstairs shop. Once inside, they leave slime and droppings all over everything. That can be removed fairly easily, but they also eat paper. Their favored diet is Motorola service manuals and white chip-board boxes. Many of my service manuals have pieces missing or the covers destroyed. My storage boxes of parts look like a bad case of leprosy. Unfortunately, I'm into ecology and simply move them outside when I find them.

I don't know. I usually just "hire" them for cash, under the table, etc. I once tried to use the UCSC student employment office, and discovered that 3 out of 3 programmers couldn't follow instructions, or complete a simple programming project. It's difficult to do everything myself, but it's still easier than hiring a student to do it, and then having to clean up the mess myself.

In terms of dollars generated, it's about 60% Windoze. Linux and SCO Unix (and Xenix) adds another 10%. The rest are imbedded systems which run on QNX and unrecognizable Linux mutations.

The official rate is about 3%.

However, I track my grocery bills, fixed expenses (insurance, satellite TV, gasoline, etc) and find 5% a more realistic number. I'll be blunt... the government lies and tweaks the numbers on unemployment and cost of living.

Nope. Long story. No insurance, but I have sufficient cash. Cash has a big advantage in that I can negotiate the cost of services and go offshore if necessary. Until my most recent monstrous medical expense, I was doing slightly better than if I had insurance. One of my rationalizations was that I was paying exactly what it would cost if the insurance companies were removed from the picture. That's the real affordable medicine. I'm not sure where Obama got the idea that insurance somehow translated into good and cheap medical care.

One of my surgeries costs me less in cash than the co-pay and non-covered items cost an acquaintance with insurance.

I retired in about 1981, but didn't realize it. I've been working for myself since then, which is close enough to retirement.

Shorts, cotton shirt, light jacket, and cheap tennis shoes. One local cyclist that drives me nuts is a seriously overweight former heart attack victim, about 45-50 years old. Every weekend, he cranks his way up Hwy 9 from Santa Cruz to Felton (about 8 miles and 800ft elevation) without ever stopping or appearing tired. His idea of a bicycle came from a junk yard. I've tried to keep up with him, and gave up early in the ride. I don't know how he does it.

The "bike lane" on Hwy 9 varies from 2ft wide down to perhaps 2 inches wide. Lots of rocks and debris in the lane. Hit a pebble with my skinny tires and I'll go sideways and possibly otto control. I've come close enough to disaster to avoid riding on Hwy 9. There are some nice quiet bike paths in the flats that are safer.

Your modem/router should have a logging feature, it should track both in and out traffic.

John

That's far from reality. At most, it's a mix desktop and laptops.

Many of us prefer desktops because when something fails we only need to replace that component. A mouse, a keyboard or a display screen. Even if the box itself fails that's all you need to replace

But laptops are made down to a price and aren't as mechanically robust. I have had two fail when the pin in the DC power socket broke off, and the current one is on its last legs because the hinge has broken.