rfarris@rfengr.com (Rick Farris) (07/26/90)
Greetings, I'm in the process of installing WD8003E ethernet cards, and I've managed to confuse myself about IP addresses. I did-the-right-thing and wrote to NIC for an IP address, but now that I'm ready to set the addresses on my WD8003s, I find nothing but a sticker saying "Network Address 0000C0 5E9A18." Where are my address jumpers? Is there a default address hardwired into the card? Does the tcp/ip driver automatically change it when the system boots? Did I buy cards that can only reside at one address? What's up with that? -- Rick Farris RF Engineering POB M Del Mar, CA 92014 voice (619) 259-6793 rfarris@rfengr.com ...!ucsd!serene!rfarris serenity bbs 259-7757
lars@spectrum.CMC.COM (Lars Poulsen) (07/27/90)
In article <1990Jul26.062713.24394@rfengr.com> rfarris@RFEngr.com (Rick Farris) writes: >I've managed to confuse myself about IP addresses. > >I did-the-right-thing and wrote to NIC for an IP address, >but now that I'm ready to set the addresses on my WD8003s, I >find nothing but a sticker saying "Network Address 0000C0 >5E9A18." Where are my address jumpers? > >Is there a default address hardwired into the card? Does >the tcp/ip driver automatically change it when the system >boots? Did I buy cards that can only reside at one address? There are two separate layers of address, and tehy are not related. The sticker shws the hardware address. It is programmed into a chip on the board and should not be changed. The IP address is what you tell the software that will speak TCP/IP. When somebody wants t send packets to your machine, they will broadcast an ARP (Address Reslution Protocol) query on the ethercable, saying in essence: "I need to speak to 123.4.5.6, but I don't know his ethernet address". The software in your machine will then reply "I'm here". Now both machines know the ethernet address that goes with the other guy's IP address, and they squirrel this knowledge away in a table. So: As hard as you try, you will NOT find a place to strap your IP address into the board. -- / Lars Poulsen, SMTS Software Engineer CMC Rockwell lars@CMC.COM
naftoli@aecom.yu.edu (Robert N. Berlinger) (07/27/90)
In article <1990Jul26.062713.24394@rfengr.com> rfarris@RFEngr.com (Rick Farris) writes: >I'm in the process of installing WD8003E ethernet cards, and >I've managed to confuse myself about IP addresses. > >I did-the-right-thing and wrote to NIC for an IP address, >but now that I'm ready to set the addresses on my WD8003s, I >find nothing but a sticker saying "Network Address 0000C0 >5E9A18." Where are my address jumpers? You're confusing IP address with Ethernet address. Each Ethernet network interface comes pre-configured with its own unique Ethernet address in the world. That's the number on the sticker. Normally there's no need to change it, but most boards allow changing the Ethernet address via software. The IP address is a higher level address for TCP/IP (level 3 of the protocol stack) that is usually configured into software. A protocol named ARP (Address Resolution Protocol) is used to map between IP and Ethernet addresses. Hope that answers your question. -- Robert N. Berlinger |Domain: naftoli@aecom.yu.edu Supervisor of Systems Support |UUCP: ...uunet!aecom!naftoli Scientific Computing Center |CompuServe: 76067.1114@compuserve.com Albert Einstein College of Medicine |AppleLink: D3913@applelink.apple.com
peiffer@cs.umn.edu (Tim Peiffer (The Net Guy)) (07/28/90)
In article <1990Jul27.060743.26946@spectrum.CMC.COM> lars@spectrum.CMC.COM (Lars Poulsen) writes: >In article <1990Jul26.062713.24394@rfengr.com> rfarris@RFEngr.com (Rick Farris) writes: [...] >So: As hard as you try, you will NOT find a place to strap your >IP address into the board. The explanation was good in that it was a good layman's description, but I see the need to have the questions answered more in terms of what to do next. The ethernet address is, as was said before, a low level address. It corresponds roughly to a hardware serial number which follows the equipment around from birth to death. The IP address is configureable vi the application's packet driver. NCSA telnet has a configuration file (config.tel) which contains all the parameters to set up the card including the IP address. An extract from the config.tel file is shown below. Tim Peiffer ----------- Tim Peiffer peiffer@cs.umn.edu or Computer Science Dept ..!rutgers!umn-cs!peiffer University of Minnesota MPLS MN 55455 ---------------------- myip=128.101.226.102 # ip types are # xx.yy.zz.qq - your IP address netmask=255.255.0.0 # needed if not using BOOTP. hardware=packet # harware choices # 3com - 3com 3c501 # 3c523 - 3com 3c523 # wd800 - Western Digitial 800E # nicpc - # nicps - # ni5210 - Micom Interlan NI5210 card -- ----------- Tim Peiffer peiffer@cs.umn.edu or Computer Science Dept ..!rutgers!umn-cs!peiffer University of Minnesota