You are TECHS, you should KNOW BETTER!

[trayce.livejournal.com]

1. I spent over half an hour with a doddery old satellite tech the other day on the phone, trying to get him to telnet onto the sat modem to check its BER reading. This involved putting the IP equiv of its MAC, plus gateway and subnet, into the winXP LAN settings. Simple enough. Only it still wouldnt connect. We faffed around in bafflement for some time, until he exclaimed: "Oh hang on a sec... I havent put the ethernet card into this laptop! That won't help will it!?"

*shoots self*

2. Tech calls in today to ask me why, when one PC worked on the link the client had, he couldn't get five PCs on a hub to do the same. "I've put all the same IP details in, and the first PC on the list works fine. But the other four wont connect. I got the subnet in as 255.255.255.252, and I've given the other PCs an IP following on from the one that works (these were PUBLIC IPs, need I add), why wont they work?"

"Uhh, sir, you only have a /30 - you only get one spare IP. You have to use DHCP for the rest and a hub won't do that you need a router or a server"

"oh ok. Is there any way around this then?"

*revives dead self, shoots self a second time*

Comments

[jecook]

Just because they are satellite techs does not mean that they are network techs.

[trayce.livejournal.com]

Ah, should have clarified that the second tech was the LAN tech they'd brought in after the dish was activated, to do the PCs on the LAN... :/

[jecook]

Ah. ::facepalms::

First thing I learned when I started in at the ISP I used to work for was subnetting and CIDR. Evil, arcane stuff, but you can do neat tricks with it.

[jahbulon.livejournal.com]

Hey quick question, do MACs convert directly to IPs through some arcane equation or is what you were doing a hardware-specific process? I don't deal with MAC addresses yet but may shortly be thrown into a position where I need to know..

[trayce.livejournal.com]

I use the calculator in windows =) I'm a bit crap at math, but the IP of a MAC always starts with 10.x.x.x so if the MAC ends in, say, 01:3a:7f you'd have 10.1.58.127 (3a and 7f being converted from hex to dec).

I only recently really learnt this myself thanks to the sat job.

[jecook]

Odd. I've never had to perform MAC to IP conversion. Y'all must be using really oddball stuff there... However, my experience is with Ethernet and "traditional" ISP gear. Never worked with the satellite gear, so they might do stuff differently.

[kayfox.livejournal.com]

I guess their system assigned ips based on MAC addys.

[trayce.livejournal.com]

(late reply) the MAC conversion is only needed to connect directly to these Linkstar modems when they're offline, ie crossover cable from PC to modem, to do diagnostics. Obv once online they have yer regular public IP space.

[kayfox.livejournal.com]

No, IPs are assigned by system administrators or software acting on their behalf.

MACs are assigned by the manufacturer of the hardware from a pool assigned to them by an industry standards body.

[lions-tambua.livejournal.com]

oh simple
set fix IPs to 192.168.0.1 - 192.168.0.5 with SBNMSK 255.255.255.0 and everything is OK
you neeed no router, no switch, just a hub and works great.
Or should it be 'Secure' ? just dont connect anywhere else (like inet) and it IS *G*