Create resolve.py

resolve.py

@@ -0,0 +1,154 @@
+#!/usr/bin/env python
+
+# Produce by Jim Reynolds - [email protected] - May 2018
+# Please contact me if you discover a bug or wish to suggest an enhancement
+
+# This command accepts a destination IP address as an argument and determines how packets to this destination will egress the N7K
+# The IP interface and the physical interface are resolved since they are not always the same.
+
+
+from cisco import cli
+import sys
+import xml.etree.cElementTree as ET
+
+no_of_args = len(sys.argv);
+
+if no_of_args == 1:
+        print 'Usage : %s <Destination IP Address>' % str(sys.argv[0])
+        exit(0);
+
+ipToResolve = str(sys.argv[1])
+DEBUG = 0
+if no_of_args == 3:
+ DEBUG=1;
+
+#DEBUG = str(sys.argv[2])
+
+def extract_arp_info():
+    #cli | xml
+        global ipToResolve
+
+
+        state = 1
+
+        while state > 0:
+                if DEBUG == 1:
+                        print 'state: %s' % state;
+                if state == 4:#Resolve interface to a port
+                        print 'Egress Port: %s' % (intf);
+                        state = 0
+
+
+                if state == 3:#Get the interface
+                        #Find egress interface for macad (state=1)
+                        if "Eth" in ifname:
+                                intf = ifname
+                                state = 4;
+                        if "Vlan" in ifname:
+                                intf = resolveMAC(macad);
+                                state = 4;
+                        print 'Egress Interface: %s' % (ifname);
+
+
+                if state == 2:
+                        #Next-Hop is not the destination. Check the interface
+                        macad = resolveARP(ipnexthop)
+                        if macad == '0000.0000.0000':
+                                #print 'No ARP entry exists'
+                                intf = ifname;
+                                #Check the IP assigned to the egress interface
+                                ipOfe = getIPofInterface(intf);
+                                #print 'The NH is asssigned to the egress interf
+ace'
+                                print 'MAC Address: Assigned to the egress inter
+face';
+                        else:
+                                print 'MAC Address: %s' % (macad);
+                        state = 3;
+
+                if state == 1:
+                        raw = cli('show ip route ' + ipToResolve + ' | xml | exc
+lude "]]>]]>"')
+
+                        # Load and parse XML
+                        tree = ET.ElementTree(ET.fromstring(raw))
+                        data = tree.getroot()
+                        ipnexthop = 'xxx';
+                        rib_info = '{http://www.cisco.com/nxos:1.0:urib}'
+                        for i in data.iter(rib_info + 'ROW_path'):
+                                ipnexthop = i.find(rib_info + 'ipnexthop').text
+                                clientname = i.find(rib_info + 'clientname').tex
+t
+                                ubest = i.find(rib_info + 'ubest').text
+                                print 'IP Next-Hop: %s, Source: %s' % (ipnexthop
+,clientname);
+                                state = 1
+                                ipToResolve = ipnexthop
+                                if clientname == 'am':
+                                        ifname = i.find(rib_info + 'ifname').tex
+t
+                                        uptime = i.find(rib_info + 'uptime').tex
+t
+                                        state=2
+                                if clientname == 'local':
+                                        ifname = i.find(rib_info + 'ifname').tex
+t
+                                        uptime = i.find(rib_info + 'uptime').tex
+t
+                                        state=2
+                                if clientname == 'hsrp':
+                                        ifname = i.find(rib_info + 'ifname').tex
+t
+                                        uptime = i.find(rib_info + 'uptime').tex
+t
+                                        state=2
+
+def resolveARP(ipadd):
+        rawARP = cli('show ip arp ' + ipadd + ' | xml | exclude "]]>]]>"')
+        treeARP = ET.ElementTree(ET.fromstring(rawARP))
+        dataARP = treeARP.getroot()
+        arpINFO = '{http://www.cisco.com/nxos:1.0:arp}'
+        for ia in dataARP.iter(arpINFO + 'ROW_vrf'):
+                count = ia.find(arpINFO + 'cnt-total').text
+                if count == '0':
+                        return '0000.0000.0000'
+
+        mac = '0000.0000.0000'
+        arpINFO = '{http://www.cisco.com/nxos:1.0:arp}'
+        for ia in dataARP.iter(arpINFO + 'ROW_adj'):
+                mac = ia.find(arpINFO + 'mac').text
+        return mac;
+
+def resolveMAC(macadd):
+        int = 'None';
+        rawMAC = cli('show mac add add ' + macadd + ' | xml | exclude "]]>]]>"')
+
+        treeMAC = ET.ElementTree(ET.fromstring(rawMAC))
+        dataMAC = treeMAC.getroot()
+        macINFO = '{http://www.cisco.com/nxos:1.0:l2fm}'
+        for ia in dataMAC.iter(macINFO + 'ROW_mac_address'):
+                int = ia.find(macINFO + 'disp_port').text
+        return int;
+
+def getIPofInterface(IPintf):
+        rawIP = cli('show ip int ' + IPintf + ' | xml | exclude "]]>]]>"')
+        treeIP = ET.ElementTree(ET.fromstring(rawIP))
+        dataIP = treeIP.getroot()
+        ipINFO = '{http://www.cisco.com/nxos:1.0:ip}'
+        for X in dataIP.iter(ipINFO + 'ROW_intf'):
+                ipa = X.find(ipINFO + 'prefix').text
+                return ipa;
+
+
+def main():
+        # Get interface information in XML format
+        print
+        print 'Resolving Destination'
+        print
+        #extract urib neighbors info
+        extract_arp_info()
+
+
+
+if __name__=="__main__":
+    sys.exit(main())