Networking For Application Developers by Roy Kim
-
Upload
roy-kim -
Category
Technology
-
view
5.128 -
download
5
description
Transcript of Networking For Application Developers by Roy Kim
IT Networking for Application DevelopersPresenter: Roy [email protected]: roykimsharepoint.wordpress.com
Agenda• Benefits of IT Networking Knowledge• Networking Fundamentals• Troubleshooting Network Devices• Troubleshooting Tools
[email protected]@wordpress.com
Benefits of Networking Knowledge• Interface with IT administrators and IT architects.
Know how to ask the right questions.
• Understand development machine and testing environments. Faster issue/resolution cycles with IT Fix your own problems
• Become a well-rounded Technology Architect Core fundamental Design application architecture with IT touch points in mind
[email protected]@wordpress.com
Network Diagram
SwitchSwitch
HostsRouter
DMZ
Subnet
Internet
Firewall Security
[email protected]@wordpress.com
Network Fundamentals• Node
Any device on a network• Host
Participate in applications in a client server model on a network.• Switch
Routing traffic within a network between hosts.• Subnet
A partition of a network that share the same network ID or subnet prefix. A grouping of network traffic into sub networks.Mitigate network congestion.
• Router Routing IP traffic between networks and subnets
[email protected]@wordpress.com
Network Fundamentals• Domain Name Resolution (DNS) Server
Host Name Resolution service Translate host name to IP Address DNS client resolver cache
• Dynamic Host Configuration Protocol (DHCP) Server Automatic assignment of an IP address to a network device. Client IP reservation - Offers static assignment
e.g. Network Printers
[email protected]@wordpress.com
Network Fundamentals• Firewall
Allow or deny network traffic on the inbound or outbound communication
Network Security Management Packet Filter Application firewall Network address translation Proxies Load Balancer E.g. Microsoft Threat Management Gateway
[email protected]@wordpress.com
TCP/IP Protocol Suite• Transmission Control Protocol/Internet Protocol• The suite of communications protocols used to connect hosts on the Internet.
[email protected]@wordpress.com
Hosts: TCP/IP ConfigurationIP Address
MAC Address
Subnet Mask
Default Gateway
DNS Server
DHCP Enabled
DHCP Server
192.168.1.100
00-50-56-C0-00-01
255.255.255.0
192.168.1.1
192.168.2.101
Yes
192.168.2.200
[email protected]@wordpress.com
SubnettingDMZ
Internet192.168.1.128
192.168.1.0 192.168.1.64
Subnet Mask 255.255.255.192 or CIDR /26Network ID 192.168.1.0
10.21.128.1
192.168.1.2
192.168.1.3
192.168.1.4
192.168.1.5
Hosts:192.168.1.66-126
Hosts:192.168.1.29-190
192.168.1.1
192.168.1.65
192.168.1.129
[email protected]@wordpress.com
Subnetting
Binary form Dot-decimal notation
IP address 11000000.10101000.00000101.10000010 192.168.5.130
Subnet mask 11111111.11111111.11111111.00000000 255.255.255.0
Network prefix 11000000.10101000.00000101.00000000 192.168.5.0
Host part 00000000.00000000.00000000.10000010 0.0.0.130
Binary form Dot-decimal notation
IP address 11000000.10101000.00000101.10000010 192.168.5.130
Subnet mask 11111111.11111111.11111111.11000000 255.255.255.192
Network prefix 11000000.10101000.00000101.10000000 192.168.5.128
Host part 00000000.00000000.00000000.00000010 0.0.0.2
[email protected]@wordpress.com
Troubleshooting Areas• Network Interface
IP Address (DHCP) ARP Cache
• Subnet or Routers or Host Route table
• Host Name Resolution DNS Server DNS client resolver cache Host file
• Firewall
[email protected]@wordpress.com
Troubleshooting Connectivity• IP Addressing
To display, ipconfig /all netsh interface ip show config
To verify, ping loopback address 127.0.0.1 ping <host IP Address>
To clear IP address, ipconfig /release To get new IP address from DHCP, ipconfig /renew IP conflict scenario To clear, arp -d
[email protected]@wordpress.com
• ipconfig
[email protected]@wordpress.com
Troubleshooting Connectivity• Arp cache
To display, arp –a
To clear, arp -d
[email protected]@wordpress.com
Troubleshooting Connectivity• Subnet Mask
To display, ipconfig /all Can set manually in Local Area Connection properties.
• Default Gateway To display, ipconfig /all Can set manually in Local Area Connection properties.
[email protected]@wordpress.com
Troubleshooting Connectivity• Verify reachability to another host
ping <remote IP address>
• Verify Route Table entries To display, route print
To clear, route –f
[email protected]@wordpress.com
Troubleshooting Connectivity• Verify reachability for intermediate routers
tracert <remote IP address>
pathping <remote IP address>
[email protected]@wordpress.com
Troubleshooting Host Name Resolution
• DNS Server• Verify DNS server response, nslookup <hostname/FQDN>• Verify DNS Server setting, ipconfig /all• ping <DNS server IP>• ipconfig /registerdns
• DNS client resolver cache• To display, ipconfig /displaydns | more• ipconfig /flushdns
• Flushes the contents of the DHS resolver cache on the local computer. Pre-loads any entries in the HOSTS file into the cache.
• NetBIOS • To display cache, nbtstat -c
• Host file Location: %SystemRoot%\system32\drivers\etc\hosts DNS client resolver cache includes host file entries
[email protected]@wordpress.com
Troubleshooting Firewall Rules
Blocks inbound and/or outbound tcp/ip traffic Client side vs Server side firewall Verify communication/connectivity in front or behind
firewall. Verify if other clients can connect View firewall rules
[email protected]@wordpress.com
Troubleshooting TCP Ports
Display ports’ state and PID, netstat –ano Display applications and ports listening, netstat –b
Verify tcp port connectivity, telnet <IP address> <TCP Port>
[email protected]@wordpress.com
Tools SummaryTool DescriptionArp Allows viewing and editing of the Address Resolution Protocol (ARP) cache.Hostname Displays the host name of the computer.Ipconfig Displays the current TCP/IP configuration for both IPv4 and IPv6. Also used to
manage Dynamic Host Configuration Protocol (DHCP)-allocated IPv4 address configurations, display or flush the DNS client resolver cache, and register DNS names.
Netsh Configuration tool for many network services. For each network service, there is a context containing commands specific for that service. For the netsh interface ip contexts, displays and administers TCP/IP protocol settings on either the local computer or a remote computer.
Netstat Displays protocol statistics and information on current TCP connections.Nslookup Performs DNS queries and displays the results.Ping Sends Internet Control Message Protocol (ICMP) Echo or Internet Control
Message Protocol for IPv6 (ICMPv6) Echo Request messages to test reachability.
Route Allows viewing of the IPv4 and IPv6 routing tables and editing of the IPv4 routing table.
Tracert Sends ICMP Echo or ICMPv6 Echo Request messages to trace the network route taken by IPv4 or IPv6 packets to a specific destination.
Pathping Sends ICMP Echo or ICMPv6 Echo Request messages to trace the route an IPv4 or IPv6 packet takes to a destination and displays information on packet losses for each router and link in the path.
Event Viewer Records errors and events.Performance Logs and Alerts
Logs TCP/IP core protocol performance and sends alerts (the SNMP service must be installed).
Network Monitor Captures and displays the contents of TCP/IP packets sent to and from computers running Windows Server 2003.
Telnet Tests TCP connection establishment between two nodes.
[email protected]@wordpress.com