Doh, I meant the /80 of 1C for interconnects. xxxx:xxxx:zz::1C:YYYY:1 and :F in a /112 ...Skeeve -- Skeeve Stevens, CEO eintellego Pty Ltd - The Networking Specialists skeeve@eintellego.net<mailto:skeeve@eintellego.net> / www.eintellego.net Phone: 1300 753 383, Fax: (+612) 8572 9954 Cell +61 (0)414 753 383 / skype://skeeve www.linkedin.com/in/skeeve ; facebook.com/eintellego -- eintellego - The Experts that the Experts call - Juniper - HP Networking - Cisco - Brocade - Arista - Allied Telesis Disclaimer: Limits of Liability and Disclaimer: This message is for the named person's use only. It may contain sensitive and private proprietary or legally privileged information. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. eintellego Pty Ltd and each legal entity in the Tefilah Pty Ltd group of companies reserve the right to monitor all e-mail communications through its networks. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorised to state them to be the views of any such entity. Any reference to costs, fee quotations, contractual transactions and variations to contract terms is subject to separate confirmation in writing signed by an authorised representative of eintellego. Whilst all efforts are made to safeguard inbound and outbound e-mails, we cannot guarantee that attachments are virus-free or compatible with your systems and do not accept any liability in respect of viruses or computer problems experienced. On 25/01/11 12:43 AM, "Skeeve Stevens" <Skeeve@eintellego.net<mailto:Skeeve@eintellego.net>> wrote: Lasse, We use /112's – last chazwazza being 65k addresses… Requires little effort in remembering the ranges…. With one end being :1 and the other :F This leaves more than enough addresses for HSRP/VRRP and all the other things like it. Also means we can introduce addressing on the link for diagnostics quite easily. We actually use the /96 of 1C (to mean 1nterConnect) - makes it recognisable to engineering staff. There is the issue of the pingpong affect, but I'm hoping vendors (if they haven't already) will introduce features to protect against it when (if) they implement RFC4443. ...Skeeve -- Skeeve Stevens, CEO eintellego Pty Ltd - The Networking Specialists skeeve@eintellego.net<mailto:skeeve@eintellego.net><mailto:skeeve@eintellego.net> / www.eintellego.net Phone: 1300 753 383, Fax: (+612) 8572 9954 Cell +61 (0)414 753 383 / skype://skeeve www.linkedin.com/in/skeeve ; facebook.com/eintellego -- eintellego - The Experts that the Experts call - Juniper - HP Networking - Cisco - Brocade - Arista - Allied Telesis Disclaimer: Limits of Liability and Disclaimer: This message is for the named person's use only. It may contain sensitive and private proprietary or legally privileged information. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. eintellego Pty Ltd and each legal entity in the Tefilah Pty Ltd group of companies reserve the right to monitor all e-mail communications through its networks. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorised to state them to be the views of any such entity. Any reference to costs, fee quotations, contractual transactions and variations to contract terms is subject to separate confirmation in writing signed by an authorised representative of eintellego. Whilst all efforts are made to safeguard inbound and outbound e-mails, we cannot guarantee that attachments are virus-free or compatible with your systems and do not accept any liability in respect of viruses or computer problems experienced. On 24/01/11 11:48 PM, "Lasse Jarlskov" <laja@telenor.dk<mailto:laja@telenor.dk><mailto:laja@telenor.dk>> wrote: Hi all. While reading up on IPv6, I've seen numerous places that subnets are now all /64. I have even read that subnets defined as /127 are considered harmful. However while implementing IPv6 in our network, I've encountered several of our peering partners using /127 or /126 for point-to-point links. What is the Best Current Practice for this - if there is any? Would you recommend me to use /64, /126 or /127? What are the pros and cons? -- Best regards, Lasse Jarlskov Systems architect - IP Telenor DK