From: Sam Munzani (sam@xxxxxxxxxxx)
Date: Wed Feb 21 2001 - 17:36:26 GMT-3
That's not the point here Justin. Outbound you can load balance easily but
can't do it for response or inbound traffic. Inbound traffic will always
come on the ISP link whose IP addresses you are using.
The cheapest way to do it is as follow.
1. Use IP scheme from ISP2. So all your return and inbound traffic will come
on ISP2 link.
2. On your internet router create a default pointing to ISP1. So all your
outbound will take this path out.
3. Have a floating static default with higher distance to ISP2 so incase of
ISP1 link failure, outbound traffic will take this way out.
Now, Nothing can save you if your ISP2 link goes down. If you want that too,
then find a 7200 series with BGP license and start doing active BGP routing.
HSRP will not help you at all in this redundant design because you are
depending mainly on your IP address block.
Your design will serve well if your are using it for internal network only
not for internet.
Regards,
Sam Munzani
CCIE # 6479, CCNP, CCDP, CCSA, MCSE, CNE 5, SCO Master ACE, HP Openview
Consultant
> The problem with HSRP is it is an Active/Passive technology, so you won't
be
> able to load balance between the two. To get a fully redundant load
sharing
> topology without using BGP you would probably need:
>
>
> DSL Cable
> R1 R2
> | |
> |---------------|
> |
> Ethernet
> |
> |---------------|
> | |
> R3 R4
> | |
> -----------------
> Internal
> Hosts
>
> You would use dynamic routing on R1 and R2 to announce default routes to
R3
> and R4.
> R3 and R4 would run HSRP on the internal network side. This means that
say
> R3 becomes the primary HSRP router, and then would load balance traffic
> between R1 and R2. If R3 fails, R4 will become primary router and will
also
> load balance between R1 and R2. If R1 or R2 fail, only 1 default route is
> announced. In this scenario, the network provides reduncancy for a single
> router failure and also a double router failure (provided the failures are
> not both R1 and R2 or both R3 and R4). The network also load balances
> between the cable and DSL connections, which would not be possible if the
> cable and DSL routers were running HSRP.
>
> Also, for a cheaper alternative for DSL, you could use Cisco 827, which
also
> supports FW/IPsec/VoIP...
>
> Regards,
>
> Justin Menga CCIE #6640 MCSE+I CCSE
> WAN Specialist
> Computerland New Zealand
> PO Box 3631, Auckland
> DDI: (+64) 9 360 4864 Mobile: (+64) 25 349 599
> mailto: justin.menga@computerland.co.nz
>
>
>
> -----Original Message-----
> From: Peter [mailto:peter@web53.com]
> Sent: Wednesday, February 21, 2001 6:08 PM
> To: Foster, Kristopher; 'Paul Thomas'; ccielab@groupstudy.com
> Subject: Re: off topic: redundant internet connections for small clients
>
>
> For the Cable connection, get a CiscoUBR924. This is a SOHO IOS router
with
> a cable interface, it even supports VoIP. For the DSL, get a 1700 with
the
> new WIC-DSL card. You can run HSRP between the two, track the WAN link,
> creat equal cost routes out for load balancing, etc. You still may have
> problems with point #2 below.
>
> Peter
>
>
> ----- Original Message -----
> From: "Foster, Kristopher" <KFoster@C1Communications.com>
> To: "'Paul Thomas'" <psthomas@telusplanet.net>; <ccielab@groupstudy.com>
> Sent: Tuesday, February 20, 2001 1:37 PM
> Subject: RE: off topic: redundant internet connections for small clients
>
>
> > You may need to look into a hardware solution (www.fatpipeinc.com may
have
> > what you need). The major problem with trying to load balance with your
> way
> > is inconsistency:
> >
> > 1. you are doing per destination load balancing, in which case if one
> > provider goes down, or a problem farther up the path occurs, you will
> > continue to forward traffic in that direction. The only way it will
fail
> > over properly is if the connected interface goes down.
> >
> > 2. you are doing per packet load balancing, other then your packets
> arriving
> > out of order or at very inconsistent rates, NAT isn't going to work
> properly
> > (which I can't see anyway of getting around having to do NAT without
> having
> > your own advertisable address space).
> >
> > If someone can come up with a decent solution I'd like to hear it too.
> This
> > is a problem I've seen come up before without resolution.
> >
> > Kris,
> >
> > -----Original Message-----
> > From: Paul Thomas [mailto:psthomas@telusplanet.net]
> > Sent: Tuesday, February 20, 2001 2:02 PM
> > To: ccielab@groupstudy.com
> > Subject: off topic: redundant internet connections for small clients
> >
> >
> > Hi all,
> > Does anyone have any suggestions on configurations to improve =
> > interent redundancy for small clients that cannot run BGP. For example a
=
> > 50-100 user company with both a Cable modem and ADSL connection. I could
=
> > see how setting up internal servers with an address from each ISP's =
> > range would allow access to them from the internet if one link went down
=
> > (as long as both addresses are listed in DNS). What could you do for =
> > internal client pc's to ensure internet connectivity? A router connected
=
> > to both the cable and ADSL modems could have both listed as default =
> > gateways and load balance between the two links to optimize bandwidth =
> > utilization. It would only fail over to the other link if the connection
=
> > between the client company and the ISP went down though. It would be =
> > unable to sense a failure in the ISP connection to the Internet backbone
=
> > for example. Any suggestions of how to optimize this setup further? =
> > Without BGP of course ;-)
> >
> > Thanks everyone,
> >
> > Paul Thomas
> >
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:28:55 GMT-3