Dear Internet Friends,

On April 20th, 2004 GDIS, received a security advisory from Cisco Systems regarding a TCP/BGP vulnerability affecting Cisco network devices. In response to this advisory, GDIS will be performing maintenance on all routers on 4/22/04 at 12:00am CDT until 6:00am CDT.

We do not anticipate any network down time as a result of this maintenance and you do not need to make any changes. The objective of this maintenance is to implement a preliminary security measure on all routers to protect the GDIS network and our customers' services from any potential exploit of this vulnerability.

This recently announced TCP vulnerability creates the potential for a DoS situation for Internet Service Providers who run the Border Gateway Protocol (BGP). An exploit of this vulnerability could allow for the constant resetting of BGP sessions between Internet routers, which would result in these providers being unable to exchange routing information.

BGP is the most commonly used protocol for exchanging routing information between Internet Service Providers. Due to the fact that GDIS maintains BGP sessions with all of our network providers, it has been deemed necessary to take precautions to shield our network from the effects of this vulnerability.

GDIS is performing this maintenance to implement the Cisco recommended workarounds for this vulnerability and avoid these potential consequences of an exploit:
- Loss of routing information between networks resulting in potential routing loops
- Packet loss due to route flapping
- Higher than normal network latency

We truly apologize for the short notice of this event; however, we feel it is critical to address this situation as quickly as possible in order to protect your business. If you have any questions, please contact our Customer Care Team.

Regards,

Francis Gibbons, President
GDIS, Inc.