Loss

My father passed away last month. I wrote some thoughts down to remind myself how I was feeling:

2007-03-23

I feel that my father's death on March 18, 2007 has cheated him, me, my mother, my siblings, my child, and my siblings' children of a man who absolutely adored his grandchildren. I did not know where my relationship with my father stood when I told him he was going to be a grandparent, and I wanted my daughter to have him as a loving grandpa. Even though he had made several invitations to my wife and me that we had often accepted, I was completely unprepared for the avalanche of support he immediately sent to me when I told him we were having a child. He was smoking several turkeys for Thanksgiving to give to the many people with whom he shared his generosity, and he announced on the phone to me that he was going to send me a turkey that day! The delicious turkey arrived by express mail in a styrofoam cooler.

When my daughter was born by an unplanned caesarean section delivery, he left Wichita Falls for Austin immediately to see his first grandchild and also Amanda and me.

I do still feel that life's events have cheated us, but I believe that God works through those who surrender their will to God's to love one another as my larger family has done abundantly since my father's death. The edges around this sudden hole in my life are made softer by the love I have been able to give and receive over the last five days since his death. Our faith tells us to comfort one another and know that we are safe in our love and God's love despite the uncertainty of life to which we are acutely aware. Knowing how much love constantly is here for us overrides the uncertainties that are simply a matter of fact.

I had been trying to express my feelings of being cheated, not by God, but by the event of my father's death when I looked up and saw a card that had been taped to his desk clearly for some time. On it was a beautiful summation of what I was feeling: "Trials are not enemies of faith but are opportunities to prove God's faithfulness."

There is still so much for me to be thankful for and sad about. I feel as if my dad's life was taken from all of us too soon. We had recently reconciled after a decade of some estrangement, and I was so happy for the role he took upon himself to reconcile us, and I feel like someone showed me a beautiful thing only yank it from my grasp as soon as I held it. I am thankful for our reconciliation, but sad and angry that simple things such as finishing my deck he helped me build will now have to be done without him, and I'm still immeasurably thankful that he did get to come help me build the deck.

My dad's oldest brother found and bought several copies of the inspirational card pictured and gave one to me on Easter that I now keep in my wallet.

Starcraft and NAT

Getting Starcraft to work for two people behind NAT

Update: Please see Jonathan's comment for v 1.16.1 for an updated set of instructions.

Ed. The symptom that this solves is that when two people are behind the same NAT gateway, they experience lots of lag in the game, and may see high latency in the Battle.net game setup. We work around this by remapping port 6112 at the NAT gateway.

This information is from Jan 18, 2007. (original)

My friend Jason and I have been figuring out how to allow two people behind a single NAT gateway router to play Starcraft through Battle.net. Limited information is found through Google on this topic, and Blizzard offers no help. We each have Linksys WRT54G routers with alternate firmware that supports running iptables. (DD-WRT and HyperWRT Thibor + tofu)

Having two people behind a single NAT gateway router connect to the same Battle.net game typically results in the appearance of lots of lag as the two clients do not communicate with each other. To get around this, the following iptables rules can be inserted on the NAT gateway or router.

In this example 70.100.200.24 is the public IP address for the two people behind the NAT router. 192.168.1.2 is the IP address of one client machine, and 192.168.1.3 is the IP address of the other client machine. On the router, type these commands as root:

(NOTE: Try using 6113 and 6114 instead of 63002 and 63003, respectively. The original rules are not working as of Starcraft version 1.16.1. I suspect that the clients outside the NAT no longer listen or respond to UDP messages on "invalid" ports such as 63002 or 63003. I hope Blizzard did not restrict all traffic to port 6112.)

iptables -t nat -I PREROUTING -p udp -d 70.100.200.24 --dport 63002 -j DNAT --to-destination 192.168.1.2:6112
iptables -t nat -I POSTROUTING -p udp -s 192.168.1.2 --sport 6112 -j SNAT --to-source 70.100.200.24:63002
iptables -t nat -I PREROUTING -p udp -d 70.100.200.24 --dport 63003 -j DNAT --to-destination 192.168.1.3:6112
iptables -t nat -I POSTROUTING -p udp -s 192.168.1.3 --sport 6112 -j SNAT --to-source 70.100.200.24:63003

The PREROUTING chain entries cause the packets to be sent to the Internet with port 63002 or 63003 rather than the standard port 6112 for Starcraft.

The POSTROUTING chain entries cause the packets to be sent on the LAN. It's important to make sure these are the first rules in their chains. I've seen other instructions that use "-A" rather than "-I" to add the rules, and this does not work for me since there are already some global rules in the chains that will handle the packets. For example, the POSTROUTING chain has a MASQUERADE target for all packets. That causes the local packets to be sent to their destinations with a LAN source address, which will be dropped by the Starcraft client because it is expecting the source address on game packets to be the public IP address.

These iptables rules will not allow one of the local machines to host the game. When we've tried that, some clients were unable to connect, so this is an issue still under some investigation. When we have time, we'll look at the Wireshark captures.