Hack the Route Start free Open app Labs / Under Load
Road 5 of 11
Under Load
Keeping a network fast and watched: TCP tuning, QoS, MTU and load balancing, what is plugged in where, management and counters, flows, logs and config backups.
Start this road, freeTCP performance, QoS, MTU & load balancing
Making connections fast and sharing a busy line.
- 01 TCP performance: bandwidth, delay, the window and loss Measure bandwidth and delay with iperf3, and watch the TCP window size react to loss. Free
- 02 Quality of service: a call and a backup on one slow line Keep a call clear beside a backup on one slow line with marking and shaping. Pro
- 03 MTU and fragmentation: when a packet is too big for the next link Send packets too big for the path and fix the downloads that hang. Pro
- 04 Load balancing: one address, many servers Put three servers behind one address, then crash one and drain another. Pro
Management & monitoring: LLDP, out of band, errors & SNMP
What each cable leads to, broken devices and counters.
- 01 LLDP and CDP: what is plugged in where Read what each device announces about itself on every cable. Pro
- 02 Out-of-band management: a way in that does not depend on the network Lock yourself out with one wrong command, then get back in another way. Pro
- 03 Interface errors: reading the counters Read an interface's counters to find drops, giants, bad frames and flaps. Pro
- 04 SNMP: asking devices how they are Poll devices with SNMP, turn counters into rates and secure it with SNMPv3. Pro
Syslog, config backups & NetFlow
Logs, config backups and traffic flows in one place.
- 01 Central syslog: every device's log in one place Send every device's log to one syslog server, then take that server down. Pro
- 02 Router config backups: TFTP, SCP and a restore Save a router's config, back it up over TFTP and SCP, and restore it. Pro
- 03 NetFlow: who talks to whom Export flows from a router and find the top talkers and a scan. Pro