Hitchhiker's Guide to Openbsd

[triggeraddr]]]]". So the first IP specified is what we want as our IP. If you have a static IP address, you 
set it here. In our example we use /0 which says that no bits of this IP address need to match and the 
whole thing can be replaced. The second IP specified is what we expect as their IP. If you know this you 
can specify it. Again in our line we don't know what will be assigned, so we let them tell us. The third 
option is our netmask, here set to 255.255.255.0. If triggeraddr is specified, it is used in place of myaddr 
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6 - Networking
in the initial IPCP negotiation. However, only an address in the myaddr range will be accepted. This is 
useful when negotiating with some PPP implementations that will not assign an IP number unless their 
peer requests ``0.0.0.0''. 
The next option used "add default HISADDR" sets our default route to their IP. This is 'sticky', meaning 
that if their IP should change, our route will automatically be updated. With "enable dns" we are telling 
our ISP to authenticate our nameserver addresses. Do NOT do this if you are running a local DNS, as 
ppp will simply circumvent its use by entering some nameserver lines in /etc/resolv.conf. 
Instead of traditional login methods, many ISPs now use either CHAP or PAP authentication. If this is 
the case, our configuration will look slightly different: 
myisp:
set phone [phone]
set authname ppp
set authkey ppp
set login
set timeout 120
set ifaddr 10.0.0.1/0 10.0.0.2/0 255.255.255.0 0.0.0.0
add default HISADDR 
enable dns
In the above example, we specify our username (ppp) and password (ppp) using authname and authkey, 
respectively. There is no need to specify whether CHAP or PAP authentication is used - it will be 
negotiated automatically. "set login" merely specifies to attempt to log in, with the username and 
password previously specified. 
Using PPP(8)
Now that we have our ppp.conf file set up we can start trying to make a connection to our ISP. I will 
detail some commonly used arguments with ppp: 
●
ppp -auto myisp
- This will run ppp, configure your interfaces and connect to your ISP and 
then go into the background. 
●
ppp -ddial myisp
- This is similar to -auto, but if your connection is dropped it will try and 
reconnect. 
If the above fails, try running /usr/sbin/ppp with no options - it will run ppp in interactive mode. The 
options can be specified one by one to check for error or other problems. Using the setup specified 
above, ppp will log to /var/log/ppp.log. That log, as well as the man page, all contain helpful 
information. 
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6 - Networking
ppp(8) extras
In some situations you might want commands executed as your connection is made or dropped. There 
are two files you can create for just these situations: /etc/ppp/ppp.linkup and /etc/ppp/ppp.linkdown. 
Sample configurations can be viewed here: 
●
ppp.linkup
●
ppp.linkdown