Change Details

With the current GREs enabled in eqiad and esams, there have been numerous small issues with the reduced MTU of 1476: T218184 T232456 T232491 [[ https://en.wikipedia.org/wiki/Wikipedia:Village_pump_(technical)#Cannot_save_edit_on_pages_when_using_cellular_network_with_mobile_device | enwiki VP ]] We have a mitigation, which is not without tradeoffs and I don't feel comfortable turning on globally for all hosts (or even all eqiad + esams). We've been applying the mitigation manually, where it will be lost on next reboot naturally. This task is track all hosts mitigated, so that we can later ensure this is all reverted if/when we have a better solution. The fix is to change the `advmss` parameter on the default route. This command turns on the mitigation idempotently: `ip -4 route replace $(ip -4 route show default) advmss 1436` And to remove it without rebooting would be: `ip -4 route replace $(ip -4 route show default) advmss 0` The current list of mitigated hosts, AFAIK, is: * archiva1001 * install1002 * cp1xxx (all) * cp3xxx (all) * cobalt (gerrit) * gerrit2001

With the current GREs enabled in eqiad and esams, there have been numerous small issues with the reduced MTU of 1476: T218184 T232456 T232491 [[ https://en.wikipedia.org/wiki/Wikipedia:Village_pump_(technical)#Cannot_save_edit_on_pages_when_using_cellular_network_with_mobile_device | enwiki VP ]] We have a mitigation, which is not without tradeoffs and I don't feel comfortable turning on globally for all hosts (or even all eqiad + esams). We've been applying the mitigation manually, where it will be lost on next reboot naturally. This task tracks all the hosts mitigated, so that we can later ensure this is all reverted if/when we have a better solution. The fix is to change the `advmss` parameter on the default route. This command turns on the mitigation idempotently: `ip -4 route replace $(ip -4 route show default) advmss 1436` And to remove it without rebooting would be: `ip -4 route replace $(ip -4 route show default) advmss 0` The current list of mitigated hosts, AFAIK, is: * archiva1001 * install1002 * cp1xxx (all) * cp3xxx (all) * cobalt (gerrit) * gerrit2001

With the current GREs enabled in eqiad and esams, there have been numerous small issues with the reduced MTU of 1476: T218184 T232456 T232491 [[ https://en.wikipedia.org/wiki/Wikipedia:Village_pump_(technical)#Cannot_save_edit_on_pages_when_using_cellular_network_with_mobile_device | enwiki VP ]] We have a mitigation, which is not without tradeoffs and I don't feel comfortable turning on globally for all hosts (or even all eqiad + esams). We've been applying the mitigation manually, where it will be lost on next reboot naturally. This task is tracks all the hosts mitigated, so that we can later ensure this is all reverted if/when we have a better solution. The fix is to change the `advmss` parameter on the default route. This command turns on the mitigation idempotently: `ip -4 route replace $(ip -4 route show default) advmss 1436` And to remove it without rebooting would be: `ip -4 route replace $(ip -4 route show default) advmss 0` The current list of mitigated hosts, AFAIK, is: * archiva1001 * install1002 * cp1xxx (all) * cp3xxx (all) * cobalt (gerrit) * gerrit2001