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Chapter 58. Networking

Verification of signatures using the MD5 hash algorithm is disabled in Red Hat Enterprise Linux 7

It is impossible to connect to any Wi-Fi Protected Access (WPA) Enterprise Access Point (AP) that requires MD5 signed certificates. To work around this problem, copy the wpa_supplicant.service file from the /usr/lib/systemd/system/ directory to the /etc/systemd/system/ directory and add the following line to the Service section of the file:
Environment=OPENSSL_ENABLE_MD5_VERIFY=1
Then run the systemctl daemon-reload command as root to reload the service file.
Important: Note that MD5 certificates are highly insecure and Red Hat does not recommend using them. (BZ#1062656)

Mellanox PMD in DPDK causes a performance drop when IOMMU is enabled inside the guest

When running Mellanox Poll Mode Driver (PMD) in Data Plane Development Kit (DPDK) in the guest, a performance drop is expected if the iommu=pt option is not set.
To make Mellanox PMD work properly, I/O memory management unit (IOMMU) needs to be explicitly enabled in the kernel, and use the passthrough mode. For doing that, pass the intel_iommu=on option (for Intel systems) to the kernel command line. In addition, use iommu=pt to have a proper I/O performance. (BZ#1578688)