Author Archives: Job Snijders
Author Archives: Job Snijders
"The separation of location and identity is a step which has recently been identified by the IRTF as a critically necessary evolutionary architectural step for the Internet."
- N. Chiappa in draft-chiappa-lisp-introduction-00An example would be that my IPv6 prefix 2001:67c:208c:10::/64 (the 'who') currently is located behind the following WAN IP addresses: 188.8.131.52, 184.108.40.206 and 2001:67C:21B4:1::2 (the 'where'). In this example my prefix is multi-homed behind 3 connections, and I'm doing IPv6 over IPv4 next to IPv6 over IPv6. This is possible because this single IPv6 prefix can have multiple Routing Locators (the 'where') and LISP is address-family agnostic.
# install this as .git/hooks/pre-commit to check Puppet manifests
# for errors before committing changes.
[ "$SKIP_PRECOMMIT_HOOK" = 1 ] && exit 0
# Make sure we're at top level of repository.
cd $(git rev-parse --show-toplevel)
trap 'rm -rf $tmpdir $tmpfile1 $tmpfile2' EXIT INT HUP
tmpdir=$(mktemp -d precommitXXXXXX)
echo "$(basename $0): Validating changes."
# Here we copy files out of the index into a temporary directory. This
# protects us from a the situation in which we have staged an invalid
# configuration using ``git add`` but corrected the changes in the
# working directory. If we checked the files "in place", we would
# fail to detect the errors.
git diff-index --cached --name-only HEAD |
grep '.pp$' |
git checkout-index --stdin --prefix=$tmpdir/
find $tmpdir -type f -name '*.pp' |
while read manifest; do
puppet Continue reading
apt-get install apache2-mpm-prefork apache2-utils apache2.2-binStep 2: obtain PGP key, configure apt Continue reading
apache2.2-common bsd-mailx libapache2-mod-php5 libapr1
libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap
libgd2-noxpm libjpeg62 libperl5.10 nagios-plugins-basic
php5-common postfix ssl-cert nagios-plugins-standard
nagios-plugins-extra git-core make
auto virbr0The above configuration will configure a bridge interface without an IPv4 address and route the /29 that was assigned to you by your ISP to that interface. This will force Linux to ARP for every IP from that /29 on this particular virbr0 interface.
iface virbr0 inet manual
post-up ip route add 10.10.10.0/29 dev virbr0
This is a response to Petr's well articulated discussion of LISP: "A High-Level overview of LISP"
He captured some of the key points that make LISP compelling, including the discussions about hierarchical routing (and associated problems with address allocations and multi-homing), the "level of indirection" enabled by LISP - due to the separation of host addresses (EIDs) and routing locators (RLOCs) - and the "push" vs. "pull" aspects of various mapping and routing systems.
There are a several areas that I think deserve greater explanation, however. The most important is regarding the LISP mapping system. "Core routing table size reduction" was the initial focus (and instigation) of LISP. But core routers are not the only ones taking full routes, some people might want the full routing table to be available on more places to have more granular control over egress traffic. Because BGP is a "push" technology, the FIB must be populated with full routes and be available in the "forwarding path" (data plane) of packets. This leads to the need for expensive silicon and memory on each line card. Where LISP helps is in two main areas. First, the LISP ALT routing table is decoupled from expensive Continue reading