First usable, 01.

Some devices allow you to use network/broadcast addresses too and this is not a problem for the LNS (you will understand because of the strange routing at the end of the mail) However, not all do, so using the +1 IP seems the best option.

The typical setups you can have in Switzerland are:

ISP <---- ppp fixed/dynamic ip ----> ADSL with nat <--- LAN private IPs (no need to explain anything here)

ISP <--- ppp with subnet other than /32 --- ADSL with multinat <--- LAN private IPs AFAIR, Multinat is the term used by ZyXEL. It means you have multiple IPs on the WAN side, however you get assigned only one but you still can do NAT entries for the other IPs of the subnet.

ISP <--- ppp with fixed/dynamic IP ---> ADSL routed <--- LAN with public range

This is the normal routed case. I think this is what Daniel was looking for. If VTX does not offer this, I know other ISPs that do it (hmmm for example.... I do :P)

<spam>We offer all three possibilities.</spam>

Perhaps for a better understanding of the curious, I can show the differencies in the radius,

The classic fixed IP:

Framed-IP-Address = 1.2.3.4 # WAN IP Framed-IP-Netmask = 255.255.255.255 # WAN MASK

The classic routed range:

Framed-IP-Address = 1.2.3.4 #WAN IP Framed-IP-Netmask = 255.255.255.255 # WAN MASK Framed-Route = 2.3.4.0/24 # LAN PREFIX

And finally the "MultiNAT" way (I find it kinda ugly..)

Framed-IP-Address = 1.2.3.129 # WAN IP Framed-IP-Netmask = 255.255.255.248 # WAN MASK Framed-Route = 1.2.3.128/25

The route here seems useless, but it is not. The Cisco takes a PPP client with a /32 mask, overriding the Framed-IP-Netmask. Therefor you have to route the other IPs to the customer. The netmask seems useless if the cisco ignores it, but you still need to send it because the PPP device (ZyXel, netscreen, whatever) really cares about it ;-)

lns01.xxx#show ip route vrf xxx xxx.xxx.xxx.65 Routing entry for xxx.xxx.xxx.65/32 Known via "connected", distance 0, metric 0 (connected, via interface) Routing Descriptor Blocks: * directly connected, via Virtual-Access328 Route metric is 0, traffic share count is 1

lns01.xxxb#show ip route vrf xxx xxx.xxx.xxx.64 Routing entry for xxx.xxx.xxx.64/29 Known via "static", distance 1, metric 0 Redistributing via ospf xxx Advertised by ospf xxx subnets route-map xxx Routing Descriptor Blocks: * xxx.xxx.xxx.65 Route metric is 0, traffic share count is 1

I hope it helped anyone to understand this...

But perhaps they are confused now ;-)

Cheers, Pascal

nearly same story as sdsl before, VTX used 2 IP out of the customer /29 range for the wan link. Traceroute looked funny, not to mention how that "improved" icmp Trouble

Cheers ...

Am 8 Jun 2007 um 1:09 hat Daniel Roethlisberger geschrieben:

Date sent: Fri, 8 Jun 2007 01:09:56 +0200 From: Daniel Roethlisberger daniel@roe.ch To: swinog@swinog.ch Subject: Re: [swinog] vtx ADSL /30 subnet practice Send reply to: swinog@swinog.ch mailto:swinog- request@lists.swinog.ch?subject=unsubscribe mailto:swinog- request@lists.swinog.ch?subject=subscribe

Pascal Gloor pascal.gloor@spale.com 2007-06-07: [snip]

...

This is the normal routed case. I think this is what Daniel was looking for.

Not quite, but oh never mind. The point I was trying to make is the fact that vtx engineers explained to a customer that he would not be able to assign *any* address of his /30 subnet to a server behind his ADSL router because all of the subnet would be consumed by the link from the LNS to the ADSL router (I guess this hasn't come across too well from my message).

It seems nobody can imagine how this is supposed to be the case, so I guess that confirms that it's probably bogus information. Thanks anyway for all responses!

Cheers Dan

-- Daniel Roethlisberger daniel@roe.ch _______________________________________________ swinog mailing list swinog@lists.swinog.ch http://lists.swinog.ch/cgi-bin/mailman/listinfo/swinog

csdatabrasil Ltda. Roger Schmid Rua Arquiteto Luiz Nunes 186 Imbiribeira CEP: 51170-430 Recife/ PE BR +55 81 3422 1714 US: +1 360 515 33 80 CH: +41 32 5110858 UK: +44 8444845331 VOIP: 3011@sip.ip-tel.ch