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LAN IP Address Advice?

Several questions about configuring IPv4 and v6 with a mix of static and DHCP LAN addresses.

1) With Comcast gateways are there a preferred ranges for DHPC assigned LAN IP and static LAN IP?


2) What DHPC lease duration is appropriate for a business with many transient devices, like a hotel or marina?


3) What should be IPv6 settings for this situation: Stateless or Stateful?


Our marina's LAN has a mix of static IP devices (PCs, cameras, access points) and dynamic IP assigned by the Comcast gateway, a Cisco DPC3939B to boater's devices. Reading forum entries I get the impression that our static IP should(?) be in the upper range rather than lower and DHCP lease time Forever.


Any advice about this for Cisco, Netgear and SMC gateways?

IPv6 is factory default. Current IPv4 setup is


Marina IP.png

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Trusted Forum Contributor

Re: LAN IP Address Advice?

Hello Docedock and welcome,


Answer to #1 : Comcast typically sets its IPV4 DHCP LAN addresses range from to for SMCD3G and NetGear3000 or to for DPC3939. The customer business networking requirements are the ultimate detemining factor as to how these are used and configured.


Answer to #2 : The lease time duration is again a direct function of customer network requirements. For example, if you use a SMC and/or NG3K Comcast Gateway (CG) and you have your own wireless router (wr), most customers want their wr connected permanantly so Leasetime=Forever would this customer's setting. Another scenario would be a DPC customer not wanting his private or public wireless users consuming permanent bandwidth, so Leasetime=1 day, 2 days, 1 week may be acceptable setting based again on specific business requirements. Leasetime=1 day for your scenario sounds very reasonable, imho.


Answer to #3 : Again, IPV6 is really a new animal and is very device dependent. Comcast offers dual IPV4 and IPV6 dual stack principally for customer's to begin getting their internal networking devices up and running. Customers use stateless when there is only a need for dynamic IP address to be doles out by the internal router. Customer's will eventually use stateful when the new static IP addressing schema is implemented. I will leave you with  one of my favorite IPV6 links that you can obtain some great additional IPV6 information.


Hope this helps you out.

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