21,391 reputation
12349
bio website ripple.com
location Oakland, CA
age 44
visits member for 3 years, 1 month
seen 2 hours ago

I am Chief Cryptographer at Ripple Labs and one of the architects of the Ripple payment system.


1d
comment Static routing on CentOS through managed switch
You're trying to solve the wrong problem. The problem is not routing these packets to the Internet, that's easy. The problem is getting the replies back.
2d
comment “Lock” a certain user to a certain user in SSH (Cygwin)?
What's the purpose of the user having SSH access? What is he supposed to be doing?
Sep
27
comment Service port accessible only by one network card
What error does the service return?
Sep
24
comment How can I have ntpdate ignore skew?
You have to bring it up to date. Modify the $cmd line to what is appropriate for your platform.
Sep
24
comment linux: raid4 without striping
Why not just use two RAID 1 volumes? You'll need one extra drive, but that seems to be a very small cost.
Sep
24
revised PING to my site url returns 100 percent but my site is still up and working
added 181 characters in body
Sep
24
answered PING to my site url returns 100 percent but my site is still up and working
Sep
24
comment How can I have ntpdate ignore skew?
Yes. Start ntp and then wait for it to report that it is synchronized. There used to be a tool called ntp-wait for this. It was a fairly trivial perl script.
Sep
24
comment How can I have ntpdate ignore skew?
There hasn't been a good reason to do this for many years now. The ntp service handles this case already. (You may want to specify appropriate options, such as -g.)
Sep
22
comment How do we find out what is causing high cache usage on our server?
You need to understand why the machine is dying, not why it is using memory. Using memory is normal, dying is not. Can you describe the problem a bit better? When it "dies", what exactly happens? Does it crash? Reboot? Respond to pings? Log something?
Sep
17
comment High memory usage, where is it coming from?
"Why is my server wasting so little memory?" (There are only two things you can do with RAM, use it or waste it. You can't save it for later. So "lots of use" means "little waste".)
Sep
15
comment Router cannot ping computers behind a switch
What ports on the router are you using?
Sep
15
comment Monitoring a switch via console port
We really need to know exactly what device you're talking about.
Sep
11
comment tcp ack delay almost 600ms, is this all right?
You seem to be expecting some unreasonable level of precision from TCP timers. It's not intended to be a real-time, low-latency service.
Sep
11
answered tcp ack delay almost 600ms, is this all right?
Sep
11
comment tcp ack delay almost 600ms, is this all right?
It looks like a packet was lost and retransmitted. The recipient didn't know the packet was lost and retransmitted, and so started a 200ms timer when it received the retransmit. A 500ms timeout over TCP is idiotic.
Sep
11
comment tcp ack delay almost 600ms, is this all right?
What client timeout are you talking about?
Sep
9
comment RAID6 generates quite a IO wait at relatively low TPS
For a given level of performance, the wait time is purely determined by load. You seem to be getting reasonable performance -- 200 TPS. (The heads have to seek.)
Sep
4
answered Why is my self-signed wildcard certificate not working?
Sep
1
comment HA router with keepalived showing unexpected traceroute
Yes, it's normal. When the device originates packets itself, it won't use the floating address.