Sandy, Please take note of the wording before jumping the gun. Teamed NICs seem to work by my account as well, but Ipswitch specifically refused to support the previous issue we had with peering due to the teamed network configuration (if you'll recall I had asked you about this odd problem with the multihomed configuration last year). Anyhow, Ipswitch insisted on having us remove the teaming configuration before continuing with support.
Chris, take it for what it's worth. Peering works well. Based on Sandy and Len's comments combined, it might help people make recommendations if you provide more information about your anticipated configuration (from an email architecture standpoint as well as network). When we migrated several servers to a newer consolidated system, we chose to use peering to allow the mail systems to co-exist as we made the transition. This was required because 140 remote sites all relied on the servers and were being upgraded & configured site by site. We found that once more than 1/2 of the accounts had been migrated to the new servers, we noticed that we were seeing a lot of duplication in emails & active SMTP delivery threads since messages were being duplicated roughly half of the time. This is compounded if your IMail servers forward all email through anti-virus / spam gateways (as the email could potentially hit the gateway twice), so the gateway servers may see some increased traffic as well. If you double your daily traffic and it is still well under capacity for a single server then this is most likely not a concern for individual server resources. Peering will reduce the burden on a server for IMAP/POP/auth requests, but may not necessarily reduce overall SMTP traffic unless using a hub & spoke / smart bridgehead type configuration which is intelligent enough to route emails to the correct server. This is less of an issue if all servers are on the same LAN. Over a WAN however, this could be an issue. This is of course entirely dependant on the amount of traffic you anticipate, and the layout of your networks. Regards, Ives ----- Original Message ----- From: "Sanford Whiteman" <[EMAIL PROTECTED]> To: "Ives Stoddard" <[EMAIL PROTECTED]> Sent: Wednesday, June 18, 2003 10:59 PM Subject: Re[2]: [IMail Forum] Peering > > 1) Ipswitch will not support NIC teaming, particularly with > > Peering... > > Strange, I've never had a prob with this (3com and Intel teaming > drivers). > > > Keep in mind that as you add the number of nodes, you add to the > > likelihood that a server will have to lookup and forward the email > > to another server. This can add traffic to your network... > > I really think very few people can saturate a LAN link with mail > traffic, since disk I/O and CPU will bottleneck much more quickly. If > a network is already taxed, it's feasible, but LAN bandwidth is > relatively cheap these days (then again, I've been able to team where > you haven't, thus doubling/tripling bandwidth at will). Vis-a-vis CPU > utilization due directly to network traffic, since a peering setup is > designed to distribute disk, network, and CPU across multiple servers, > overall host resource consumption should go down as you add more > servers (even if ratios shift to more network resources being used). > > If WAN connections are being used, one does have to be much more > careful and truly model traffic to determine how much will be > intra-peer, how much will be inter-peer, how much remote delivery from > a peer to the outside. > > Also on the high end, if your network latency and number of peers keep > SMTP delivery processes open for prolonged periods of time, you could > starve the local machine if it's also trying to perform local delivery > and message retrieval. This is why I recommend using asymmetric or > "bridgehead" peers that have no local userbase, thus eliminating > resource contention with mailbox server tasks. > > -Sandy > > > ------------------------------------ > Sanford Whiteman, Chief Technologist > Broadleaf Systems, a division of > Cypress Integrated Systems, Inc. > e-mail: [EMAIL PROTECTED] > ------------------------------------ > > > To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html > List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ > Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ > To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
