EX16-MB-000380 - The Exchange Receive Connector Maximum Hop Count must be 60.

Information

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.

Solution

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

or

Enter the value as identified by the EDSP that has obtained a signoff with risk acceptance.

Repeat the procedure for each Receive connector.

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_MS_Exchange_2016_Y21M07_STIG.zip

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-5(2), CAT|III, CCI|CCI-001095, Rule-ID|SV-228384r612748_rule, STIG-ID|EX16-MB-000380, STIG-Legacy|SV-95393, STIG-Legacy|V-80683, Vuln-ID|V-228384

Plugin: Windows

Control ID: 3a012cfb0765edf7711c379445f4ba7beae207a29511b338db729acae7118b34