The Exchange Receive Connector Maximum Hop Count must be 60.
An XCCDF Rule
Description
<VulnDiscussion>Email system availability depends in part on best practice strategies for setting tuning configurations. This setting controls the maximum number of hops (email servers traversed) a message may take as it travels to its destination. Part of the original internet protocol implementation, the hop count limit prevents a message being passed in a routing loop indefinitely. Messages exceeding the maximum hop count are discarded undelivered. Recent studies indicate that virtually all messages can be delivered in fewer than 60 hops. If the hop count is set too low, messages may expire before they reach their destinations. If the hop count is set too high, an undeliverable message may cycle between servers, raising the risk of network congestion.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-259678r942348_rule
- Severity
- Low
- References
- Updated
Remediation - Manual Procedure
Update the EDSP to specify the "MaxHopCount" value or verify that this information is documented by the organization.
Open the Exchange Management Shell and enter the following command:
Set-ReceiveConnector -MaxHopCount 60