Robtex

Up: 206.227.136.0/23
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Down left: 206.227.137.0/25
Down right: 206.227.137.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
206.227.137.21	PTR	txu-totalcomp.com
206.227.137.21	PTR	txuelectric.com
206.227.137.21	PTR	txuflexdimension.com
206.227.137.24	A+PTR	www10.txu.com
206.227.137.24	A+PTR	www11.txu.com
206.227.137.25	A+PTR	galaan.txu.com
206.227.137.26	A+PTR	xmpp.energyfutureholdings.com
206.227.137.26	A+PTR	palanhi.txu.com
206.227.137.29	A+PTR	fs.tcehqa.net
206.227.137.29	A+PTR	txugroup.net
206.227.137.36	A	webtest.txu.com
206.227.137.37	A	marmaduke.txu.com
206.227.137.39	A	nsdns01.oncor.com
206.227.137.44	A+PTR	ftp.oncor.com
206.227.137.44	A+PTR	ftp.txu.com
206.227.137.44	A	ftp.luminant.com
206.227.137.49	A+PTR	luminantpw.luminant.com
206.227.137.50	A+PTR	dns02.txu.com
206.227.137.50	A	mmxsmtp01.oncor.com
206.227.137.51	A	ppmft.txu.com
206.227.137.52	A	mailhost2.txu.com
206.227.137.61	A	teem.txu.com
206.227.137.62	A	mdctxuwiis14.oncorgroup.com
206.227.137.70	PTR	streetlights.txuelectricdelivery.com
206.227.137.70	A	streetlights.oncor.com
206.227.137.70	A	streetlights.oncorgroup.com
206.227.137.71	A+PTR	maximotest.oncorgroup.com
206.227.137.71	PTR	maximotest.txuelectricdelivery.com
206.227.137.72	PTR	maximo.oncor.com
206.227.137.72	PTR	maximo.txuelectricdelivery.com
206.227.137.72	A	maximo.oncorgroup.com
206.227.137.73	PTR	maxweb.txuelectricdelivery.com
206.227.137.73	A	maxweb.oncorgroup.com
206.227.137.74	A	maxwebtest.oncorgroup.com
206.227.137.75	PTR	acis.txuelectricdelivery.com
206.227.137.75	A	esbdmz03.oncorgroup.com
206.227.137.78	A+PTR	mdcsentry.energyfutureholdings.com
206.227.137.79	A	xmpp.energyfutureholdings.com
206.227.137.79	A	efhocs.energyfutureholdings.com
206.227.137.81	A+PTR	e-contract.txuenergy.com
206.227.137.126	A	tango.energyfutureholdings.com
206.227.137.127	A	mdctxuwiis15.txu.com
206.227.137.150	A	mmxsmtp01.oncor.com
206.227.137.151	A	mmxsmtp01ob.oncor.com
206.227.137.151	A	mmxsmtp01ob.txu.com
206.227.137.152	A	eas.txucorp.com
206.227.137.170	A	mdctxuteemiis.oncorgroup.com
206.227.137.175	A+PTR	txucorp.com
206.227.137.177	A+PTR	txugas.com
206.227.137.179	PTR	oncor.com
206.227.137.193	PTR	ac.txuelectricdelivery.com
206.227.137.193	A	accomm.oncor.com
206.227.137.199	A	acdist.oncor.com
206.227.137.219	A	autodiscover.luminant.com
206.227.137.219	A	legacy.energyfutureholdings.com
206.227.137.219	A	autodiscover.txu.com
206.227.137.220	A	efhocs.energyfutureholdings.com
206.227.137.240	A+PTR	mdcxgss01.energyfutureholdings.com
206.227.137.240	A+PTR	mdcxgss01.txu.com
206.227.137.245	A+PTR	mdcxc01c.txu.com
206.227.137.246	A	sync0n.txu.com