22,448 reputation
12451
bio website ripplelabs.com
location Oakland, California
age 45
visits member for 3 years, 7 months
seen 4 hours ago

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


Mar
10
answered How does a router get its IP address assigned?
Mar
10
comment What if you set your static IP to that of Google?
BGP is probably the most important one to understand. Note that pretty much nothing a typical user can do will have any effect on their ISP's BGP activity. It is very, very important to understand that routing on the Internet is policy driven -- it doesn't take the shortest path but the one that's paying for the service.
Mar
10
answered What if you set your static IP to that of Google?
Mar
2
comment Apache starts up with high memory usage. Why?
It's really not clear what you're asking about. What specifically in all that output concerns you? Are you asking about physical memory or virtual memory? And which indications do you think are "high" and why?
Feb
27
comment modem rejects logon credentials If I try to connect through http://modem/. works fine if I connect with http://<ipaddr>/
It's not clear, at least to me, what your specific question is. I have all kinds of answers I could give you, but I have no idea which one is the one you're looking for. (If it's "what should I do next", the obvious next step is to confirm that it's the Host header that's the relevant difference.)
Feb
25
answered Routing on outgoing data packet in linux kernel?
Feb
25
comment Is it possible to find a computer's physical location in a room?
It depends on the precise details of the hardware you're working with and what kind of access you have. For example, if they have USB ports and you can deploy software to them, you can deploy a program that causes a system to alert you (say, by email) when a new USB device connects to it. Then just attach a USB flash drive to each machine in turn, keeping track of the connection order.
Feb
21
comment passenger-memory-stats doesn't show Private memory consumption
Likely your operating system doesn't track what memory usage is private.
Feb
20
awarded  domain-name-system
Feb
16
comment Remove SSL warning with internal websites, with Chrom
@MikeMestnik The client has to additionally verify that the certificate is appropriate for the URL specified. Just knowing that the cert was issued by the CA is insufficient, as an attacker can easily get a cert (and matching key) signed by a trustworthy CA. This question is dealing with those appropriateness checks, not certificate validity checks.
Feb
13
comment Is there any reason to keep the power option on default “Balanced” instead of “high performance”?
You are incorrect that the only negative effect is the electricity bill. There are several other negative effects that come from the additional heat produced and temperatures of the components, including an increased risk of performance loss due to thermal throttling. (And the CPU may not be the only component that thermally throttles.)
Jan
26
comment Apache accepting requests to other servers?
Welcome to the Internet. Everyone who operates a server on the Internet has to have a strategy for dealing with the "baseline noise" that pretty much all Internet servers see.
Jan
21
comment Apache 2.4 prefork, MySQL 5.6 and 2GB RAM
Your top output shows 1.4GB of RAM (68%) inactive, which means it's available for use for any purpose. Why do you think there's a problem?
Jan
16
revised Server virtual processors and processing units
deleted 1 character in body
Jan
15
answered Server virtual processors and processing units
Jan
13
comment kworker consuming +90% IO and zero disk write
You may want to use perf to find out what kworker is doing as a troubleshooting step.
Jan
13
comment Where is my RAM going?
Use slabtop to see if it's the dentry cache.
Jan
7
comment Linux is sending ARP requests to hosts in other subnets?
Something is probably wrong in the netmasks or routing table on host A.
Jan
6
answered Why wouldn't I want to enable swap?
Jan
6
comment svchost.exe -k regsvc using over 1.2 GB RAM
How did you determine that it was using over 1.2 GB of RAM? (Please be as specific as possible. What tool did you use? What exactly did it report?)