My home network is currently accessing the 6bone via a configured
tunnel to Hurricane Electric on a Solaris box. Currently, I'm using a
ppp over ssh tunnel to access my (NAT'ed) home network from my NetBSD
laptop at work. What I would like to do is set up the tunnel to also
route my ipv6 traffic.

e.g.,
               3FFE:1200:3028:812f::/64
  HE  ======= Solaris --------------------- NetBSD 
      ip.tun0    |         192.168.5/24
                 |
                 | (3ffe:1200:3028:812f:fca1:1db2:2c42:fcf1)
                 | ppp-over-ssh
                 |
             Linux NAT
                 | (private ip's)
                 |
            NetBSD Laptop (3ffe:1200:3028:812f:4821:5875:cf47:b087)

Using this setup, I'm able ping ipv6 addresses:

(ack)[0]/home/ack/mike$ ping6 www.netbsd.org
PING6(56=40+8+8 bytes) 3ffe:1200:3028:812f:4821:5875:cf47:b087 -->
3ffe:8050:201:1860:290:27ff:feab:19a7
16 bytes from 3ffe:8050:201:1860:290:27ff:feab:19a7, icmp_seq=0 hlim=59
time=114.877 ms
16 bytes from 3ffe:8050:201:1860:290:27ff:feab:19a7, icmp_seq=1 hlim=59
time=159.23 ms
16 bytes from 3ffe:8050:201:1860:290:27ff:feab:19a7, icmp_seq=2 hlim=59
time=118.351 ms
^C
--- www.netbsd.org ping6 statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max/std-dev = 114.877/130.819/159.230/20.139 ms

However, ipv6 connections are failing because of MTU. I've played with
the MTU settings using ifconfig and route, without any luck (from
playing with ping -s, the max packet size is 476 bytes). I realize
ppp-over-ssh is pretty ugly, but it's convenient. Does anyone have any
suggestions on changes I can make to make this work? Alternate setups I
should be using?

Thanks!
-- 
Michael Santos
mike@ethmoid.org


NetBSD Laptop:

# uname -a
NetBSD ack 1.5Y NetBSD 1.5Y (ack) #0: Sun Sep 16 07:59:46 EDT 2001
root@ethmoid:/usr/a/src/sys/arch/i386/compile/ack i386

# ifconfig ppp0
ppp0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 524
        inet 10.7.7.1 -> 10.7.7.2 netmask 0xfffffffc
        inet6 fe80::200:86ff:fe21:1184%ppp0 -> :: prefixlen 64 scopeid 0x2
        inet6 fe80::9db7:3ad8:da74:703f%ppp0 -> fe80::51d4:6bf8:8df6:34bf%ppp0 prefixlen 128 scopeid 0x2
        inet6 3ffe:1200:3028:812f:4821:5875:cf47:b087 -> 3ffe:1200:3028:812f:fca1:1db2:2c42:fcf1 prefixlen 64


Solaris server:

# uname -a
SunOS eft 5.8 Generic_108528-09 sun4u sparc SUNW,UltraAX-e

# ifconfig ppp0 inet6
ppp0: flags=2200851<UP,POINTOPOINT,RUNNING,MULTICAST,NONUD,IPv6> mtu 1500 index 15
        inet6 3ffe:1200:3028:812f:fca1:1db2:2c42:fcf1/128 --> 3ffe:1200:3028:812f:4821:5875:cf47:b087 

# ifconfig ppp0
ppp0: flags=10008d1<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST,IPv4> mtu 524 index 15
        inet 10.7.7.2 --> 10.7.7.1 netmask fffffffc 
        ether 0:0:0:0:0:0