[cobalt-users] Re: Why do cobalts have two ethernets anyhow?

[Bruce Timberlake <bruce@xxxxxxxxxx>]

> I am curious why (some, eg.xtr, 550) cobalts have two ethernet
> interfaces. You can alias many ips to a single interface, which is how
> virtually hosted sites do it.

Flexibility, mainly.  And it's so negligible cost-wise to add a 2nd NIC 
it's almost why NOT have 2?  Almost every product, with the exception of 
the early MIPS RaQ 1 and 2, has 2 NICs.  RaQ 2 even had a RaQ 2+ model 
with dual NICs at one point, and I think the early CacheRaQ2 was based on 
that setup.

Many people do their backups or administration over a "private" 
interface/network to reduce traffic on the public interface and/or for 
security.

Also as an OEM platform, a 2nd interface might be needed.  Example: the 
former Phoenix Firewall product, based on the RaQ.  Or the Symantec 
Velociraptor, based on the RaQ 4i and XTR, where they actually added a 
dual NIC to the PCI slot for a total of 4 interfaces.

Many datacenters will not have 2 cables strung to each server, so for a 
widespread ISP deployment, it's really "extra"

That's why the RaQ 4 "base" model was created, with a single NIC and no PCI 
slot. For those who needed neither, it dropped the price a coupla bucks.

> In any case what to do interfaces gain you? Anything with security or
> ipchains/iptables configurability. Anything with greater throughput?

Not really.  There are some projects out there that let you bind multiple 
interfaces together for a "fat" pipe, but I don't think a "locked down" 
Cobalt config would be too friendly to that.