Slow connection using CARP interface

  • Hello everybody

    My installations of pfsense 2.4.4-p3 works very well with CARP/HA, SYNC and XMLRPC.

    The problem is in the internet transfer rates. When using the outbound NAT of the CARP WAN interface rates are around 4 Mbps download and 9 Mbps upload.

    If in the NAT configuration I use the IP of the local WAN interface speed is within the expected; rates are around 60 Mbps download and 90 Mbps upload.

    When the parent pfsense is shut down, secondary pfsense starts working, but the problem persists.

    For testing purposes, I removed the CARP/HA configuration and added the secondary IP before that associated with CARP on the WAN interface and obtained the same satisfactory result in the two NAT output situations.

    In this cluster we have another public connection with the internet and we do not have problems of speed.

    Clearly the problem is related to the CARP/HA of this interface/connection.

    Both pfsense instance are installed on two different vmware esxi hosts, but I have already tested with both VMs on the same esxi host, with same issue

    VLAN's and switchs appear to be within the standards.


    Rate transfer using WAN CARP interface


    Rate transfer using WAN local interface

  • LAYER 8 Netgate

    There is nothing special about CARP/HA here. It's all just MAC addresses, IP addresses, and ARP. If there is something being treated differently about it it must be upstream in your environment.

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