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Most @Home subscribers use 1 v 1 DHCP that means you will get the same ip every time.
The progress is like following:
1. When your Cable modem turned on, it will send DHCPDISC to Cable Router in our Regional Center. Normaly it is a Cisco, some are Motorola or 3COM. The cable router check its "IP-HELPER" then send your broadcast to DHCP Server.
2. DHCP servers are normaly SUN E4500 Clusters, it uses Cisco AIC DHCP software or JOIN DHCP software. We are now slowly immigrating from Cisco AIC to JOIN because CISCO one are unneccessarily complicate. When DHCP receive your DHCPDESC, it will send back a DHCPOFFER which contains the available servers info.
3. Your Cable Modem then send back a DHCPREQ, the Server use your
Cable modem's MAC address to contact its database using LDAP.
When it found the ip according to your MAC, then will give back a DHCPACK.
4. Your Cable modem got the ip and finished its init. It's turn for your Computer.
Your login program send out your Customer ID (CPE_ID) through the Cable modem.
DHCP server use your CustomerID to query the database to find out
your ip then same way give back a DHCPACK, telling you the DNS server address and Your Gateway address.
Now you can surf.
In most cases, you can set your ip as a static one. Remember to setup
correct DNS address and Gateway address.
Some of Rogers' Head End use Dynamic one ( very few), they will give a new CPE Ip address from its ip pool every time.
You will cause conflict if they made changes to the ip block planning.
We always block you if that happens. :)
After all, it is safe to set your ip to a static one.
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