BugZero | F5 BugID 508656 - v11.5.1-hf7 EngHF 129 (Zebos) breaks 255.255.255.2...

F5 - Defect ID: 508656

v11.5.1-hf7 EngHF 129 (Zebos) breaks 255.255.255.255 VAddr needed for DHCP relay

F5 - Defect ID: 508656

v11.5.1-hf7 EngHF 129 (Zebos) breaks 255.255.255.255 VAddr needed for DHCP relay

Last updated on July 18th, 2026

BugZero Risk Score
8.4 High

Overall: 8.4

Severity: 9.1

Community: 4.2

Lifecycle: 7.0

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Bug Details

Priority: 2-Critical
Status: Verified
Impact Category: TMOS

Description

Symptoms

On installing EngHF the DHCP relay VAddr (255.255.255.255) is incorrectly validated to be in error by mcpd.

Impact

Unable to load config.

Conditions

Install EngHF

Workaround

Change virtual address to something other than 255.255.255.255

Fix Information

None

Change history

Links

Original Vendor Announcement

Relevant Products

Click on a version to see all relevant bugs

Affected versions:11.5.1, 11.5.1 hf1, 11.5.1 hf2, 11.5.1 hf3, 11.5.1 hf4, 11.5.1 hf5, 11.5.1 hf6, 11.5.1 hf7, 11.5.1 hf8, 11.5.1 hf9, 11.5.1 hf10, 11.5.1 hf11, 11.5.2, 11.5.2 hf1, 11.5.3, 11.5.3 hf1, 11.5.3 hf2, 11.5.4, 11.5.4 hf1, 11.5.4 hf2, 11.5.4 hf3, 11.5.4 hf4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.0 hf1, 11.6.0 hf2, 11.6.0 hf3, 11.6.0 hf4, 11.6.0 hf5, 11.6.0 hf6, 11.6.0 hf7, 11.6.0 hf8, 11.6.1, 11.6.1 hf1, 11.6.1 hf2, 11.6.2, 11.6.2 hf1, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3

Fixed versions: No known fixed versions

Relevant Products

Click on a version to see all relevant bugs

Fixed versions: No known fixed versions

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F5 - Defect ID: 508656

v11.5.1-hf7 EngHF 129 (Zebos) breaks 255.255.255.255 VAddr needed for DHCP relay

F5 - Defect ID: 508656

v11.5.1-hf7 EngHF 129 (Zebos) breaks 255.255.255.255 VAddr needed for DHCP relay

Last updated on July 18th, 2026

BugZero Risk Score8.4 High

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

F5 - Defect ID: 508656

v11.5.1-hf7 EngHF 129 (Zebos) breaks 255.255.255.255 VAddr needed for DHCP relay

F5 - Defect ID: 508656

v11.5.1-hf7 EngHF 129 (Zebos) breaks 255.255.255.255 VAddr needed for DHCP relay

Last updated on July 18th, 2026

BugZero Risk Score8.4 High

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

BugZero Risk Score
8.4 High

BugZero Risk Score
8.4 High